exercise judicial or quasi- judicial functions, are part of a group of “new- style” courts.^13
These courts enjoy compulsory jurisdiction and allow nonstate actors to litigate. They
not only resolve disputes but also assess state compliance with international law and
review the legal validity of state and international legislative and administrative acts.
Thus, even without a central enforcer, they have a significant impact.
Likewise, the Eu ro pean Court of Justice of the Eu ro pean Union is a strong court,
serving as a significant source of Eu ro pean law. It has a heavy caseload, covering virtu-
ally every topic of Eu ro pean integration, and it does have an enforcement mechanism,
as discussed earlier in this chapter.
National and even local courts are also sources of international law. Such courts
have broad jurisdiction: they may hear cases occurring on their territory in which
international law is invoked, or cases involving their own citizens who live elsewhere;
they may hear any case to which the princi ple of universal jurisdiction applies. Under
universal jurisdiction, states may claim jurisdiction if an individual’s conduct is suf-
ficiently heinous to violate the laws of all states. Several states claimed such jurisdic-
tion because of the genocide in World War II and, more recently, for war crimes in
Bosnia, Croatia, Rwanda, and Sierra Leone, among others. In the Eu ro pean Union,
national and local courts are a vital source of law. A citizen of an EU country can ask
a national court to invalidate any provision of domestic law found to be in conflict
with provisions of the EU treaty. A citizen can also seek invalidation of a national law
found to be in conflict with self- executing provisions of community directives issued
by the EU’s Council of Ministers. Thus, in the Eu ro pean system, national courts are
both essential sources of Eu ro pean community law and enforcers of that law.
compliance and enforcement of International law
Why, then, in the absence of an international executive and an international legisla-
ture, and with only a weak international court having limited authority, do states
voluntarily comply with international law? We can understand the answer in terms of
self- interest. Both realists and liberals agree that international law compliance relies
generally on states and their individual self- interest. States benefit from participating in
making the rules through treaties, or else they would not participate in making or rati-
fying them; they can ensure, through participation, that those rules will be compatible
with their interests. States benefit from knowing that other states generally re spect ter-
ritory, airspace, and property rights, that international products and people are safe to
move across national borders, and that diplomats can safely carry out their duties with
international protection. States find it beneficial to “lock in” their commitment, for both
domestic and international tranquillity. And, thus, states comply most of the time.
Some liberals might point to the ethical argument that compliance occurs because
it is the “right thing to do.” States want to do what is right and moral, and international
244 CHAPTER SEvEn ■ IGOs, InternatIOnal law, and nGOs