International Customary Law and Antipersonnel
Landmines: Emergence of a New Customary Norm
Susan Benesch, Glenn McGrory, Cristina
Rodriguez, Robert Sloane
Allard K. Lowenstein International Human
Rights Clinic, Yale Law School
I. Why Is Customary International Law
Important For a Ban on Antipersonnel Landmines?
There are two primary sources of international
law, treaties and custom.1 Custom -- law that
develops from commonly agreed-upon rules of behavior -- 2
is important for the ban against antipersonnel landmines, because of a
critical attribute that distinguishes it from treaty law. Whereas a treaty
legally binds only those states which are parties, in most cases customary
international law constrains all states,3 even
those that have not agreed to it.4
If the Mine Ban Treatys 5
prohibitions on the production, use and transfer of landmines become part
of customary international law, then, states that are not party to the
treaty will bear a legal obligation to obey those prohibitions. For that
reason, now that a ban on antipersonnel landmines is established as treaty
law, we believe the next step is to work toward the crystallization of
a customary international law ban on landmines.
To that end, this paper will explain the
nature of customary law and its formation, and then will examine the state
of that law with respect to landmines. We will consider the following questions:
is there a customary international norm6 against
the use of antipersonnel landmines now, and if not, can we expect such
a norm to emerge in the future? If so, when?
The most powerful force toward the establishment
of custom on landmines is the Mine Ban Treaty itself. Treaties are often
the first step in the formation of custom, especially when, as in this
case, they express consensus on the part of an extraordinary number of
states. 7 Not only do [treaties] carve out
law for the immediate parties, but they also have a profound impact upon
general customary law for nonparties,8 as
the scholar Anthony DAmato has noted. Once a rule attains the status of
customary international law, states may not unilaterally repudiate it,9
and newly emerging states will be deemed to accede to the rule as a condition
of statehood.10
This paper will show that there is rapid
momentum toward a customary norm against the use of antipersonnel landmines.
It is difficult to predict how quickly the norm will crystallize, and any
prediction would immediately become the subject of debate, but we think
most legal scholars and practitioners would agree that a customary prohibition
against landmines will crystallize in the near future.
The International Campaign to Ban Landmines
and other advocates can use customary law to argue that states should sign
the treaty. If a ban on landmines is likely to emerge soon as customary
international law, as we argue, there are two good reasons for states to
sign and ratify the convention and begin work toward compliance. First,
they will avoid being caught in violation of a binding customary norm.
Second, if states will be constrained by the new custom anyway, they will
do better to enjoy the benefits of participation in the Landmine Ban treaty
regime, including the exchange of equipment, material and scientific and
technological information for mine-clearance, and the opportunity to propose
amendments to the Convention.11
These arguments are becoming stronger with
each extra signature, ratification, or decision to forsake the use of antipersonnel
landmines, since those steps bring the international community closer to
a customary norm against the weapons.
What is Customary International Law
and How is it Formed?
According to Oppenheim, one of the most
widely-recognized authorities in international law, a custom is a clear
and continuous habit of doing certain actions which has grown up under
the aegis of the conviction that these actions are, according to international
law, obligatory or right.12 Custom is law
not because it is printed on paper, but because states practice it, and
because their officials believe it to be law.13
A sometimes slippery concept, custom plays an especially large role in
international law, where there is no legislature to codify law.(Treaty-writing
is often a slow and unwieldy process.)
The formation of custom how and when
a new norm becomes part of customary international law is the reason
for customs slippery reputation, since it is so difficult to pinpoint.
It has become the subject of substantial debate.14
In particular, scholars and judges debate the relationship between customary
international law and treaties, focusing on when and how treaties can give
rise to custom.
There have been undeniable changes in the
formation of international treaty law, brought on in large measure by the
human rights movement. The Mine Ban Treaty itself is one of the most prominent
demonstrations of new methods for drafting international treaties, and
for seeing them into law.15 The Mine Ban Treaty
proved that treaties can be negotiated faster than ever before, but this
does not necessarily mean that custom on landmines will form faster. And
since treaties are more tangible than custom, it is easier to track changes
in the formation of treaties than changes in the formation of custom.
The key questions for our purposes are:
what actions or statements, by states or other bodies, are now considered
evidence of custom? Where is the threshold between custom and non-custom,
if it is possible to find one? To answer these questions, this section
will outline the traditional understanding of custom and its formation.
Then it will examine cases in which custom forms before a practice has
become universal, since that is likely to happen in the case of the antipersonnel
landmines ban. We willthen consider whether any state can exempt itself
from a future customary norm against antipersonnel landmines by becoming
a persistent objector. Finally, we will discuss the ways in which treaties
can give rise to customary international law.
The formation of custom: practice and opinio
juris
1. General Standards
The traditional starting-point for discussions
of customary international law is also the most widely-recognized statement
as to the sources of international law: Article 38(1) of the Statute of
the International Court of Justice.16 The article
lists four sources of law:
a. international conventions, whether general
or particular, establishing rules expressly recognized by the contesting
States;
b. international custom, as evidence of
a general practice accepted as law;
c.he general principles of law recognized
by civilized nations;
d. subject to the provisions of Article
59, judicial decisions and the teachings of the most highly qualified publicists
of the various nations, as subsidiary means for the determination of rules
of law.
Since custom is not codified or printed,
like a treaty, it must be identified in a different and more complex way.
The formulation quoted in Article 38(1)(b), international custom as evidence
of a general practice accepted as law, includes the two classic requirements
for customary international law: practice and opinio juris. 17
Practice refers to the conduct of a state -- whether it uses antipersonnel
landmines, for example. Opiniojuris, short for opinio
juris sive necesitatis, can be translated as a conviction that a rule
is obligatory. It refers to state officials sense of a legal obligation
to follow a certain practice, and it is sometimes called the belief element.
Practice can be universal and still not
establish custom, if there is no opinio juris in favor of the practice.
Widespread practice without opinio juris is often called usage.
Examples are ceremonial salutes at sea and the cancellation of parking
tickets issued to diplomatic cars.18 While
states commonly do these things, no one would claim that they must
do them. This distinction between usage and custom reaches back to the
French scholar Francois Génys use of the phrase to differentiate
legal custom from usage or mere social custom.19
International courts have repeatedly affirmed
the critical role played by opinio juris in custom. In the 1927
Lotus Case, the Permanent Court of International Justice considered
whether custom had formed on a question of jurisdiction, after a French
ship and a Turkish ship collided, killing eight Turkish nationals. Turkey
began to prosecute the first officer of the French ship, and France disputed
Turkeys jurisdiction to try him. The Court was asked to decide whether
customary international law prohibited Turkey from trying the French officer.
The fact that France had abstained from trying him did not indicate custom,
the court found, since there was no evidence of opiniojuris.
It held that only if such abstention were based on [states] being conscious
of having a duty to abstain would it be possible to speak of an international
custom.20
In 1969 the International Court of Justice
(which succeeded the earlier Permanent Court) affirmed the role of opiniojuris in the North Sea Continental ShelfCases. To
decide the cases, the Court had to determine which provisions of the 1958
Geneva Convention on the Continental Shelf had become customary law by
1969, only 11 years after the Convention. It held that for a treaty provision
to become customary, two conditions must be fulfilled. Not only must the
acts concerned amount to a settled practice, but they must also be such,
or be carried out in such a way, as to be evidence of a belief that this
practice is rendered obligatory by the existence of a rule of law requiring
it The states concerned must therefore feel that they are conforming to
what amounts to a legal obligation. 21 In
1986, the Court reaffirmed this notion of opinio juris, when it
decided that under customary international law, the United States mining
of Nicaraguan harbors and financial support for the contra war was
illegal. In that decision, called the Case Concerning Military and Paramilitary
Activities In and Against Nicaragua, the Court considered whether the
principle of non-intervention in the affairs of other states had become
custom. Regarding state actions that constitute custom, it held that Either
the States taking such action or other States in a position to react to
it, must have behaved so that their conduct is evidence of a belief that
this practice is rendered obligatory by the existence of a rule of law
requiring it.22
Evidence of opinio juris can be
found in any of several types of sources. Comments by state officials may
indicate a sense of legal obligation to follow or not follow certain conduct.
Opinio juris can also be found in General Assembly resolutions,
and in other unilateral or collective statements. In the 1986 Nicaragua
case, the International Court of Justice observed that state consent to
General Assembly resolutions and other statements expressing norms embodied
in a treaty should not be understood as mere reiteration or elucidation
of treaty commitments. Rather, such expressions provide additional evidence
that the state accepts the validity of thesenorms, and consequently, also
evince an opinio juris supporting their status as customary international
law. The attitude referred to expresses an opinio juris respecting
such rule (or set of rules), to be thenceforth treated separately from
the provisions, especially those of an institutional kind, to which it
is subject on the treaty-law plane . . .23
It is important to note that an apparent
contradiction, or Catch-22 is inherent in the doctrine: opinio juris
is a prerequisite for customary law, but in order to produce opinio
juris, state officials must be convinced that the law already exists.
The paradox has been widely debated by scholars, some of whom dispute it.
In any case the apparent paradox has not prevented acceptance of customary
law essentially as here defined.24
Having described the nature of the traditional
requirements for custom, we can now ask, to what extent is it possible
to quantify them? How many states must follow a certain practice in the
belief that it is law, for international customary law to crystallize?
We know of no credible numeric rule. How many States are required to establish
general practice and how frequent, numerous and consistent the practice
must be are questions which cannot be answered in categorical propositions,
according to the scholar Oscar Schachter. Generality, frequency, density,
consistency, duration are in principle required but whether they are met
in regard to a specific rule depends on the circumstances of the case."
25 Even if it is not possible to say that custom
will have formed when a certain precise number of states has signed or
ratified the Landmine Ban, we can draw clear conclusions about other requirements
for custom, and, more encouragingly, about non-requirements.
No minimum length of time is required
for the formation of custom
There is no minimum length of time required
for the formation of custom, so the speed of the Landmine Ban process will
not hinder the bans development into custom. In the North Sea Continental
Shelf Cases, the International Court of Justice dismissed time as a
requirement for the emergence of custom from conventions. The Court held
that even without the passage of any considerable period of time, a very
widespread and representative participation in the convention might suffice
of itself, provided it included that of States whose interests were specially
affected.26
Some scholars even argue that custom can
form instantly on a new body of law, where there is no prior practice
that has to change for custom to crystallize, and where a large number
of states express unanimity. The most commonly cited example is theinternational
law on outer space 27. Instant custom cannot
be said to have formed in the case of antipersonnel landmines, since there
was longstanding practice contrary to the new norm and since states did
not reach consensus all at once.
On the lack of a time restriction, the
scholar Ian Brownlie has commented: Provided the consistency and generality
of a practice are proved, no particular duration is required: the passage
of time will of course be a part of the evidence of generality and consistency.
A long (and, much less, an immemorial) practice is not necessary, and rules
relating to airspace and the continental shelf have emerged from fairly
quick maturing of practice.28 The scholar
Malcolm Shaw concurs: in international law there is no rigid time element
and it will depend upon the circumstances of the case and the nature of
the usage in question.29
Not all states must consent to a norm
of customary international law
There is also broad agreement that general
custom does not require universal consent of States.30
In the Nicaragua case described above, the International Court of
Justice held specifically, The Court does not consider that, for a rule
to be established as customary, the corresponding practice must be in absolutely
rigorous conformity with the rule. In order to deduce the existence of
customary rules, the Court deems it sufficient that the conduct of States
should, in general, be consistent with such rules, and that instances of
State conduct inconsistent with a given rule should generally have been
treated as breached of that rule, not as indications of the recognition
of a new rule. 31
Therefore the landmines ban can become
custom, according to this formulation, even while some states still refuse
to sign the land mine treaty. Those states would then be bound by the new
custom.
It seems particularly important that states
whose interests are specially affected comply with the Landmine Ban,
for its provisions to become customary. Even while dismissing the importance
of time as a requirement for custom, the International Court of Justice
twice emphasized, in the North Sea Continental Shelf Cases, that
specially affected states would have to be parties to the 1956 Convention,
for it to becomecustomary international law.32
And in its 1996 Advisory Opinion on nuclear weapons, the Court identified
states that have nuclear weapons as a specially-affected class.33
By analogy in the case of the Mine Ban Treaty, specially-affected states
would probably be producers and users of landmines, like Russia, China,
and the United States.
The formation of custom can be based
on opinio juris more than on state practice
Many judges, scholars and legal practitioners
say that opiniojuris should be more important than practice
in the formation of custom. These jurists argue that a rule need not be
universally followed before it can be anointed as an international customary
norm it just has to be universally, or generally, defended. This argument
could be very useful in the case of antipersonnel landmines, if states
cease to defend the use of landmines before they actually stop using
them. This may be true of Angola, for example.
The call for emphasis on opiniojuris is not new. Already in 1967, Prof. R.R. Baxter wrote, Reliance
on a multilateral treaty as evidence of customary international law is
not conditional on any demonstration that the signatory States have actually
observed the norms of the treaty for any length of time. The process of
establishing the state of customary international law is one of demonstrating
what States consider to be the measure of their obligations. The actual
conduct of States in their relations with other nations is only a subsidiary
means whereby the rules which guide the conduct of States are ascertained.34
In that view, practice is subsidiary to opinio juris.
Both the International Court of Justice
and the International Criminal Tribunal for the Former Yugoslavia (ICTY)
have used this view of opiniojuris in major recent decisions
on the formation of international custom. In both cases, the courts held
that custom had crystallized, based on evidence of opiniojuris,
not practice.
In the 1986 Nicaragua case, the
International Court of Justice held that the United States had violated
customary international laws against the use of force against another state,
against intervention in another states affairs, and against violating
another states sovereignty. Since laws like the ban on non-intervention
had been violated frequently and famously, especially during the Cold War,
the Court might have had difficulty arguing for custom based on practice.
Instead it relied heavily on opiniojuris. The Court decided
that there was customary law against intervention although many states
had intervened in others affairs, because the intervening states had not
justified their conduct by reference to a new right of intervention or
a new exception to the principle of its prohibition.35
That is, the intervening states practice
did not conform to the principle, but their opiniojuris
did, so the Court concluded that there was customary law. This could apply
to the Landmines Ban. If it becomes possible to argue that although some
states use landmines, they do not defend the practice as a right or an
exception to the principle of prohibition, to borrow language from the
Nicaragua case,36 it would be possible
to argue that there is customary law against the use of landmines, following
the reasoning of Nicaragua.
Similarly, in its Appeals Chamber decision
in the Tadic case, the ICTY relied overwhelmingly on government
statements, rather than evidence of state practice, to decide in its decision
in the case of Dusko Tadic. 37 As the scholar
Theodor Meron has pointed out, the Court used various indications of opinio
juris, including military manuals, to conclude that the Court had jurisdiction
to preside over cases dealing with war crimes committed in internal armed
conflicts, not only international wars.38
Many provisions of international treaty
law, especially those regarding human rights, have given rise to undisputed
custom even though they are frequently violated. One example is the text
of the Universal Declaration of Human Rights, a code that is lavishly praised
but is still not practiced by many states. As the scholar Louis Sohn
put it, The Declaration, as an authoritative listing of human rights,
has become a basic component of international customary law, binding all
states, not only members of the United Nations.39
Even a relatively conservative source like the Restatement (Third) of Foreign
Relations Law of the United States holds that [a] state violates international
law if, as a matter of state policy, it practices, encourages or condones
cruelties against its own nationals including torture, systematic racial
discrimination, and prolonged arbitrary detention.40
All of these human rights violations are prohibited by the Universal Declaration
and other treaties,41 and there is general
agreement that they have become customary law, yet unfortunately they are
common in many states.
Opinio juris can also change quickly,
according to some scholars. They argue that since World War II, prospective
inquiry reflecting the massive proliferation of treaty law has supplanted
the retrospective inquiry that was the standard method of identifying customary
international law before. According to the scholar Ted Stein, Whereas
traditionally, [t]he question of what states ought to do was answered primarily
by asking what they have done . For todays foreign ministry lawyer, the
key question is whether to place reliance upon a rule stated in some treaty
or resolution .Correspondingly, opinio juris is no longer seen as
a consciousness that matures slowly over time , but instead as a conviction
that instantaneously attaches to a rule believed to be socially necessary
or desirable.42
These precedents suggest that a customary
norm against antipersonnel landmines could develop, even before all states
cease to use the weapons. By analogy, torture has never ceased as a practice,
but that did not stop a customary norm against torture from developing:
what counted was the development of opiniojuris. In sum,
when the ban on landmines gathers such strength that no states officials
are willing to defend the use of landmines in any circumstances, it will
be possible to argue that the ban is customary international law, like
the prohibition against torture. Of course substantial evidence of changing
practice is still necessary, otherwise the norm would be divorced from
reality. There has already been considerable change in landmines practice,
as we will discuss below.
No state can be a persistent objector
to a customary ban on antipersonnel landmines
As described above, once a rule attains
the status of customary international law, states may not unilaterally
repudiate it,43 and newly emerging states will
be deemed to accede to the rule as a condition of statehood.44
This principle admits of one exception, however, the so-called persistent
objector rule: [a] state that has persistently objected to a rule is
not bound by it, so long as the objection was made manifest during the
process of the rules emergence.45 The
persistent objector exception to customary international law derives
from recognition that international law emanates from the consent, whether
tacit or express, of independent sovereign states.Consequently, a state
that has manifestly and continuously46 objected
to an evolving norm of customary international law cannot be bound by it.47
There are almost certainly no persistent
objectors to the Mine Ban Treaty. States that wish to claim exemption from
emerging norms must make their objections manifestly and continuously,
and prior to the moment when these norms crystallize into clear customary
international law. Where, as here, a widely subscribed treaty is contributing
to the rapid crystallization of a customary norm, that means a state would
need to have compiled a record of steady objection to the treaty.48
It would seriously damage the treatys
chances of giving rise to customary law if any of the three major user
and producer states, Russia, China and the United States, was a persistent
objector. We contend that this is not possible. The United States, far
from clearly and continuously manifesting its dissent from provisions of
the Mine Ban Treaty, has been a strong supporter of many of the treatys
provisions. The United States cannot credibly claim persistent objector
status.
Nor does it appear that any other nation
has clearly and continuously dissented from the terms of the Mine Ban
Treaty or its emerging concomitant customary international law norms. In
December 1996, the United Nations General Assembly, by a vote of 156-0,
with ten abstentions, passed a resolution urging states to pursue vigorously
an effective, legally binding international agreement to ban the use, stockpiling,
production and transfer of antipersonnel landmines and call[ing] upon
States that have not yet done so to declare and implement such band moratoriums
and restrictions . . . at the earliest possible date.49
China and Russia, which have not, to date, signed the treaty, nonetheless
joined the United States at a landmine conference held at the time of the
treaty ceremony, in which all three nations indicated that they will eventually
comply with most of the treatys regulations.50
And finally [w]hile some [states] in the Middle East/North Africa region
are very hostile to a landmine banat this timeincluding Egypt, Iraq, Israel,
Libya, and Syrianearly every country has expressed support for a ban at
some point in the future.51
Treaties as a Source of Custom
As mentioned above in Section I, treaties
are a major source of customary international law, because they are an
important indicator of state commitment to emerging norms. This gives reason
to hope that the Mine Ban Treaty will give rise to custom.
The principle that customary law can develop
from the provisions of treaties is so well-established that it is codified
in the Vienna Convention on the Law of Treaties.52
It has also been repeatedly recognized by the International Court of Justice,
and by many scholars.53 In section II(A)1 above,
we have already mentioned the Nicaragua case, in which the Court
found that custom against intervention in the affairs of other states had
emerged from the U.N. Charter. As the Court pointed out in that case, customary
international law need not be identical to the provisions of the treaty
from which it emerges. Therefore if custom develops against landmines,
it is possible that its scope may ultimately be broader than the treaty
itself, so that non-party states would be bound by a more stringent norm.
Treaties dealing with the conduct of war,
especially, have given rise to a great deal of customary international
law. For example in the war crimes case of United States v. Von Leeb
(The High Command Case) the Nuremberg Tribunal concluded that the 1929
Geneva Prisoners of War Convention could be binding on Nazi Germany with
respect to the Soviet Union, although the Soviet Union had not been a party
to the convention. Only 12 years had passed since the convention had been
adopted, but the Tribunal determined that it was already customary law.54
Similarly, many provisions of the more recent Geneva Protocols of 1977
have developed into customary international law, according to the scholar
and judge Antonio Cassese, Theodor Meron and others.55
The provisions of human rights treaties
have also contributed to a substantial body of customary international
law, as many authorities including the U.S. State Department have recognized.
In a brief submitted to the U.S. court hearing the case of Filartiga v.
Pena-Irala, in which the family of a man tortured to death in Paraguaybrought
civil suit against the torturer, the State Department adopted the view
that there is a customary international norm against torture. Relying heavily
on opiniojuris, the State Department notedthat both
multilateral treaties and international custom evince a universal condemnation
of torture. 56
What is the Existing State of Customary
International Law Regarding an Antipersonnel Landmines Ban?
Although the campaign to ban antipersonnel
landmines is of recent origin, the international community has long concerned
itself with regulating the conduct of war so that it does not unduly harm
civilians. Much of this law has already become customary, as mentioned
in the previous section, and it could arguably be deemed to prohibit antipersonnel
landmines. Therefore a framework of customary international law against
landmines already exists, even if there is not yet an explicit customary
ban against them.
Three principles of longstanding, customary
international humanitarian law can be applied to antipersonnel landmines,
and arguably prohibit them. Those principles are: the rule against needlessly
aggravating human suffering, the rule against indiscriminate weapons (those
that fail to distinguish between civilians and soldiers), and the rule
that weapons must be militarily necessary. All three have been codified
in the laws of war, also known as humanitarian law. These laws are briefly
described below.
The Declaration of St. Petersburg of 1868,
in which the parties renounced the use of projectiles below a certain weight,
was an early international attempt to limit the way in which war is conducted.
The Declaration called on states not to use certain weapons that caused
(militarily) needless suffering, stating that the only legitimate object
which states should endeavor to accomplish during war is to weaken the
military force of the enemy . . . .57 The
next major codification of the laws of war emerged from the international
Hague Conferences of 1899 and 1907. The Hague Declarations and Treaties
of those dates established principles against weapons that indiscriminately
or disproportionately kill and wound civilians. The Hague Convention (II)58
The four Geneva Conventions for the Protection
of War Victims, promulgated in 1949, went into more detail, attempting
to protect wounded and sick combatants, prisoners of war, and civilians.59
More recently, Protocol I Additional to the GenevaConventions of 1949,
signed in 1977, sought to protect civilians during international armed
conflicts. Additional Protocol I emphasizes that "[i]n any armed conflict,
the right of the Parties to the conflict to choose methods or means of
warfare is not unlimited." 60 Additional Protocol
II to the Conventions extends the protections stated in the Additional
Protocol I to victims of non-international armed conflicts.61
It is easy to see how the principles of
international humanitarian law apply to landmines. First, antipersonnel
landmines needlessly aggravate human suffering, especially when they remain
in the earth long after war has ended, continuing to kill civilians including
children. Second, antipersonnel landmines are indiscriminate by definition:
since they detonate automatically, they make no distinction between an
enemy soldier, a soldier from the same army that laid the mine, a farmer,
or a child. It has been pointed out elsewhere that the use of landmines
may theoretically be discriminate, if they are directed against military
objectives, but their effects become indiscriminate whenever they are left
in the earth near civilians.62 This is so in
the overwhelming majority of the countries that contain major minefields.
Third and finally, many military experts argue that antipersonnel landmines
are not militarily necessary, although this point is still the subject
of debate.63
IV. Changes in State Practice and Opinio
Juris Concerning Antipersonnel Landmines
The Ottawa Process and the Mine Ban Treaty
have brought about a sudden, dramatic change in state practice regarding
landmines, and an even more rapid change in opiniojuris.
64As the British journalist John Ryle described
it: Its the first time that a weapon in common use has been withdrawn
from the arsenal. Its also the first timethat the manufacture, possession,
transfer, and use of an armament have been banned in a single, unambiguous
piece of legislation. The relentless pressure of the campaigners has kept
the treaty free of loopholes.65 The fact that
forty states ratified the treaty in only nine months demonstrates the power
of anti-landmine governments, non-governmental organizations (NGOs), and
international agencies to bring about change in worldwide state practice.66
Especially within the glacial world of arms control,67
the speed of the process has been striking. It reflects both the pressing
nature of the landmines problem and emerging international consensus on
the issue.68 The United Nations has referred
to the Mine Ban Treaty as a convention of conscience, that acquired force
of binding international law with historic speed. The remaining challenge
is to universalize the Treaty.69
As noted above, a treaty can form the basis
for a customary norm of international law. For two reasons, this is especially
likely to happen in the case of the Mine Ban Treaty. First, the Mine Ban
Treaty has already been embraced by most of the international community,
in opinio juris if not yet in practice. Second, some states have
already eliminated landmines from their arsenals. As discussed above, even
treaties that are regularly violated, like the Convention Against Torture,
can serve as the basis for customary international law. In the case of
the Mine Ban Treaty, as in the case of the torture convention, even non-party
states have expressed support for the ban.
The Mine Ban Treaty also strikes at the
heart of states security concerns, banning a weapon that many states have
long regarded as central to their capacity to defend themselves. In many
states, powerful national security or defense establishments feared that
the treaty would impinge on their authority. This has made it a difficult
treaty for many countries to sign, not merely an easy, symbolic gesture
in hypothetical support of human rights. Yet more than 80 percent of the
worlds nations have signed the Treaty70 and
67 countries have ratified it, reflecting states willingness to make significant
concessions to the Treatys purpose of ridding the world of landmines.
This tide of opiniojuris demonstrates the unusual strength
of the rapidly-emerging norm against antipersonnel landmines.
V. Conclusion: Development of a Customary
International Norm that Will Bind All States
In sum, we contend that a comprehensive
ban on landmines is rapidly emerging as a customary norm of international
law. Activists and sympathetic governments should realize that in working
to persuade more countries to sign and ratify the Mine Ban Treaty and to
stop using landmines, they are simultaneously working to establish customary
international law. The two processes are parallel.
A powerful argument can be made that customary
international law will have crystallized on the issue when China, Russia,
and the United States, the three remaining major users of landmines, subscribe
to the ban against them, or, at least, when those states cease to defend
their use of the weapons. As discussed above, there is no minimum length
of time that need elapse first, and we believe no state will be able to
claim persistent objector status.
Of course, the only way to verify that
custom has crystallized is to submit the question to an international court,
as in the North Sea Continental Shelf , NuclearWeapons
and Nicaragua cases discussed above.71
We have explained how one might eventually argue that customary law has
crystallized on the antipersonnel landmines ban. In the not-distant future,
landmine activists might consider submitting the matter to the International
Court of Justice.
1 Anthony A.
DAmato, The Concept of Custom in International Law, p. 4 (1971).
2 Malcolm N.
Shaw, International Law, 2nd edition (1986) p. 59, citing Unger,
Law in Modern Society (1976). For further discussion of the meaning of
custom and its importance in international law see Oppenheims International
Law, 9th edition (1992), p. 25, citing Gianni, La coutume en
droit international (1931), Thirlway, International Customary Law and Codification
(1972) et al.
3 Vienna Convention
on the Law of Treaties, opened for signature May 23, 1969, UNTS Regis.
No. 18,232, UN Doc. A/CONF.39/27 (1969) reprinted at 8 ILM 679 (1969);
North Sea Continental Shelf Cases (FRG/Den.: FRG/Neth.), 1969 ICJ Rep.
3, 198, paragraph 71, (describing the way in which customary law would
emerge from a treaty provision which, while only conventional or contractual
in its origin, has since passed into the general corpus of international
law, and is now accepted as such by the opiniojuris, so
as to have become binding even for countries which have never, and do not,
become parties to the Convention.).
4 Shaw, supra
note 2, p. 79, (stating where treaties reflect customary law then non-parties
are bound, not because it is a treaty provision but because it reaffirms
a rule or rules of customary international law.). The only states not
bound by a customary norm are those that systematically oppose it, known
as persistent objectors. This is discussed in Section II(C).
5 Convention
on the Prohibition of the Use, Stockpiling, Production and Transfer of
Antipersonnel Landmines and On Their Destruction. Henceforth, Mine Ban
Treaty or the treaty. Note that there is no legal distinction between
convention and treaty. A treaty is defined in the Vienna Convention
on the Law of Treaties as an international agreement concluded between
states in written form and governed by international law, whether embodied
in a single instrument or two or more related instruments and whatever
its particular designation. Supra note 3, Art. 2(1)(a).
6 We use the
word norm in its legal sense, so that customary norm is synonymous
with customary law.
7 When the treaty
entered into force on March 1, 1999, 134 governments had signed it and
65 had ratified it. See http://www.hrw.org/campaigns/mines/1999/icbl.
8 DAmato, supra
note 1, p. 104.
9 Jonathan I.
Charney, The Persistent Objector Rule and the Development of Customary
International Law, 56 Brit. Y.B. Intl L. 1, 2. (1985).
10 SeeVienna
Convention on the Law of Treaties, supra note 3, Article 38 (Nothing in
articles 34 to 37 precludes a rule set forth in a treaty from becoming
binding upon a third State as a customary rule of international law);
see also Ted L. Stein, The Approach of the Different Drummer: The Principle
of the Persistent Objector in International Law, 26 Harv. Intl L.J. 457,
458 (1985).
11 Supra note
5, Art.6, describing technical cooperation, and Art. 13, on amendments.
12 Oppenheims
International Law, 9th edition (1992), p. 27.
13 See, e.g.,
The North Sea Continental Shelf Cases, supra note 3, paragraph 77 (describing
the belief requirement: The States concerned must therefore feel that
they are conforming to what amounts to a legal obligation. The frequency,
or even habitual character of the acts is not enough.).
14 See, e.g.
Harold Hongju Koh, Is International Law Really State Law? 111 Harv. L.
Rev. 1824 (1998); but see Curtis A. Bradley & Jack L. Goldsmith, Federal
Courts and the Incorporation of International Law, 111 Harv. L. Rev. 2260
(1998); Curtis A. Bradley & Jack L. Goldsmith, Customary International
Law as Federal Common Law: A Critique of the Modern Position, 110 Harv.
L. Rev. 815 (1997).
15 Supra, note
7.
16 Statute of
the International Court of Justice, art. 38(1), annexed to the U.N. Charter.
17 See, e.g.,
Rudolf Bernhardt, Customary International Law, in: R. Bernhardt (ed), Encyclopedia
of Public International Law, Volume I (1992), p. 901; DAmato, supra note
1; Mark W. Janis, An Introduction to International Law p. 41-54 (1993).
18 Ian Brownlie,
Principles of Public International Law, p. 5 (1990).
19 Shaw, supra
note 2, p. 62, citing Gény, Méthode dinterprétation
et sources en droit privé positif (1899).
20 The Lotus
Case, 1927 P.C.I.J. , Series A, No. 10, 1927, p. 28.
21 North Sea
Continental Shelf Cases, supra note 3, paragraph 77.
22 Case Concerning
Military and Paramilitary Activities In and Against Nicaragua (Nicar. v.
U.S.), 1986 I.C.J. 14 (Merits Judgment, June 27), (1986), paragraph 205,
quoting The North Sea Continental Shelf Cases, I.C.J. Reports 1969, paragraph
77.
23 Id, paragraphs
188, 191.
24 American
Law Institute, Restatement (Third) of the Foreign Relations Law of the
United States (1987) Reporters Notes to § 102.
25 Oscar Schachter,
International Law in Theory and Practice, p. 9 (1991).
26 Supra note
3, paragraph 73.
27 Mark E. Villiger,
Customary International Law and Treaties p. 28, paragraph 75 (1985) citing
Res 1721 A(XVI) of 20 December 1961, and Res 1962 XVIII of 13 Decembr 1963
containing the Declaration of Legal Principles Governing the Activities
of States in the Exploration and Use of Outer Space. Villiger notes other
scholars claims for instant custom, but is skeptical of that notion himself.
28 Brownlie,
supra note 18, p. 5.
29 Shaw, supra
note 2, p. 63.
30 Brownlie,
supra note 18; Stein, supra note 10, p. 458 (stating that this standard
does not require universal participation, nor the participation of the
state to which the rule is applied.)
31 Supra note
22, paragraph 186.
32 Supra note
3, paragraphs 73, 74.
33 Advisory
Opinion on the Legality of the Threat or Use of Nuclear Weapons, 1996 I.C.J.
226 (July 8), reprinted in 35 I.L.M. 809 (1996).
34 R.R. Baxter,
Multilateral Treaties as Evidence of Customary International Law, 41 Brit.
Y.B. Intl L. 275, 300 (1965-66).
35 Supra note
22, p. 109, paragraph 207.
36 Id.
37 Prosecutor
v. Tadic, Decision on the Defense Motion for Interlocutory Appeal on Jurisdiction,
Case No. IT-94-AR72 (1995), p. 48-74, paragraphs 86-145.
38 Theodor Meron,
The Continuing Role of Custom in the Formation of International Humanitarian
Law, 90 Am. J. Intl L. 238, 240 (1996).
39 Louis Sohn,
The New International Law: Protection of the Rights of Individuals Rather
than States, 32 Am. U. L. Rev. 1, 16 (1982).
40 American
Law Institute, Restatement (Third) The Foreign Relations Law of the United
States § 702 (1987).
41 See the Convention
Against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment,
39 U.N. GAOR Supp. (No. 51) 197, U.N. Doc. A/39/51 (1984). It is interesting
to compare this treaty with the Landmine Ban Treaty. In both cases, NGOs
helped to develop public consensus in many countries, perhaps contributing
to the unusually rapid development of opiniojuris and customary
law.
42 Stein, supra
note 10, p. 465.
43 Charney,
supra note 9, p. 2.
44 Stein, supra
note 10, p. 458.
45 Id. (emphasis
added); see also Charney, supra note 9, p. 2 (noting that virtually
all authorities maintain that a State which objects to an evolving
rule of general customary international law can be exempted from its obligations).
46 Stein, supra
note 10, p. 459.
47 But see Charney,
supra note 9, p. 24 (concluding that the persistent objector rule
is, at best, only of temporary or strategic value in the evolution of rules .).The
persistent objector principle, moreover, may itself admit of exception
for certain jus cogens norms, peremptory rules of international
law from which no derogation is permitted (e.g., the prohibition against
genocide.) The threshold of state practice and opinio juris needed
to establish that some customary international law rule is jus cogens,
however, remains extremely high; at present, customary international law
concerning landmines almost certainly fails to rise to this level.
50 Howard Williams,
125 Nations Line up to Sign Treaty Banning Anti-Human Landmines,
Agence France-Presse, Dec. 3, 1997.
51 Human Rights
Watch, North African Countries Urged to Ban Landmines (visited Jan.
28, 1999) <http://www.hrw.org/press/1999/jan/naf0125>.
52 Vienna Convention
on the Law of Treaties, supra note 10, Art. 38.
53 See, e.g.
Baxter, supra note 33, p. 294.
54 11 Trials
of War Criminals Before the Nuernberg Military Tribunals Under Control
Council Law No. 10, p. 462 (1948). Also see Theodor Meron, The Geneva Conventions
as Customary Law, 81 Am. J. Intl. L., p. 359 (1987).
55 Antonio Cassese,
The Geneva Protocols of 1977 on the Humanitarian Law of Armed Conflict
and Customary International Law, 3:55 Pacific Basin L.J. 1984; Meron, Id.
56 Memorandum
for the United States as Amicus Curiae, Filartiga v. Peña-Irala,
630 F.2nd 876 (2nd Cir. 1980) (No. 79-6090), reprinted
in 19 I.L.M. 585 (1980).
57 The Declaration
of St. Petersburg, signed on 29 November, 1868, 1 A.J.I.L. (Supp.) 95-96
(1907).
58 See, e.g.
Treaty (II) with Respect to the Laws and Customs of War on Land (Hague
II), Article 239(e), prohibiting the use of arms, projectiles or material
of a nature to cause superfluous injury and the Treaty (IV) Respecting
the Laws and Customs of War on Land (Hague IV).
59 Convention
for the Amelioration of the Condition of the Wounded and Sick in Armed
Forces in the Field (Geneva Convention No. I) Aug. 12, 1949, 75 UNTS 31;
Convention for the Amelioration of the Condition of the Wounded, Sick and
Shipwrecked Members of the Armed Forces at Sea (GenevaConvention No. II),
Aug. 12, 1949, 75 UNTS 85; Geneva Convention Relative to the Treatment
of Prisoners of War (Geneva Convention No. III), Aug. 12, 1949,75 UNTS
135;Convention Relative to the Protection of Civilian Persons in Time of
War (Geneva Convention No. IV), Aug. 12, 1949, 75 UNTS 287.
60 Protocol
Additional to the Geneva Treatys of 12 August 1949, Relating to the Protection
of Victims of International Armed Conflicts (Protocol I), Aug. 15, 1977,
1125 U.N.T.S. 3, 3608, 16 I.L.M. 1391, 1391442
61 Protocol
Additional to the Geneva Treatys of 12 August 1949, Relating to the Protection
of Victims of NonInternational Armed Conflicts (Protocol II), Aug. 15,
1977, 1125 U.N.T.S. 609, 609699, 16 I.L.M. 1443, 1443449.
62 Landmines:
A Deadly Legacy, The Arms Project, Human Rights Watch, and Physicians for
Human Rights, 275.
63 See, e.g.
Antipersonnel Landmines: Friend or Foe? A Study of the Military Use and
Effectiveness of Antipersonnel Mines. International Committee of the Red
Cross, 1996.
64 This section
was prepared using secondary sources, before the final versions of the
Landmine Monitor reports were available. The reports are authoritative
for any data on state practice.
65 See John
Ryle, City of Words, The Guardian, Dec. 8, 1997, at 5.
66 Office of
the Secretary General, UN Press Briefings, Press Conference Marking the
Fortieth Ratification of Landmines Convention Triggering March 1999 Entry
into Force, http://1www.un.org//.
67 John Ryle,
The Landmines Ban and its Discontents, New York Review of Books,
Nov. 5, 1998, p. 61.
68 Id.
69 UN Press
Briefing, Press Conference on Antipersonnel Mine Convention, Oct. 1, 1998
http://1www.un.org//.
70 See China,
Russia, US feeling the heat for not signing landmine pact, Agence France-Presse,
Dec. 2, 1998.
71 Such a case
need not be filed by one state against another. The International Court
of Justice also issues advisory opinions, like the NuclearWeapons
one.