The legal analysis in the Lawyer's Primer stands unchanged since 1991, although three caveats are in order. The major caveat relates to the idea that the higher profile uses of armed force since 1991 have involved so-called humanitarian intervention. This seemingly departs from existing customary law and is typically justified in a textual interpretation of U.N. Charter Article 2(4). The argument is that support of human rights is a purpose of the United Nations, Q.E.D. use of force in their defense is consistent with Article 2(4)'s purposes language. Humanitarian intervention had been debated in the American international law community since the 1970s more or less as an offshoot of human rights ideas, but only seemed to become part of United States practice in terms of government policy during the 1990s. Humanitarian intervention continues to be opposed in diplomatic terms particularly by China and Russia. Beyond theoretical issues, their problem is that, if humanitarian intervention were permitted elsewhere, what about their minorities....
 

The original example of high profile humanitarian intervention involved the no-fly zones established over Iraq in the wake of the Gulf War, formally justified in terms of hindering Iraqi military actions against Iraq's own minority populations (Kurds in the North and Shiite Muslims in the South). There was a legal argument whether the various Security Council resolutions in the Gulf War encompassed the no-fly zones, but the better answer is that they did not. The United States refrained from pushing the matter by seeking an express authorization under a new resolution precisely because Russia and China as Permanent Members of the Security Council would not have agreed to any such resolution and would have vetoed it had such a measure come to a vote. The secondary issue then becomes whether enforcement of the no-fly zones themselves has combined with a claimed opinio juris to create new customary law under the classic formulation that customary law is created by the combination of State practice and opinio juris.
 

Humanitarian intervention was mooted in Rwanda-Burundi, but the international community hesitated rather than getting seriously involved in what was perceived as preventing genocide. The former Yugoslavia is where humanitarian intervention has cropped up again, first in Bosnia-Herznogovina but now most directly in the NATO campaign conducted against Serbia in an attempt to stop ethnic cleansing directed against ethnic Albanians in Kosovo. The international community currently recognizes Kosovo as part of Serbia, attempting to stay away from self-determination claims by Kosovo's ethnic Albanian minority (which separatist claims are associated with the Kosovo Liberation Army or KLA). There were originally some relatively weak arguments that Serbian actions against ethnic Albanians were a threat to international peace because they could cause broader armed conflict in the Balkans. This argumentation represented an attempt to justify coercive measures employing more traditional U.N. Charter Article 39 arguments asserting that events inside a country have international effects. However, since the NATO bombing campaign started no serious challenge has been raised that armed force is being used against Serbia as a sovereign State in an attempt to make it stop mistreating its own citizens on its own territory. Russia's hefty reaction to the military operation demonstrates the problem in claiming that there is sufficient opinio juris to support humanitarian intervention in general. We shall see how the precedent is judged after the smoke clears. The problem is that, while Slobodan Milosevich is now rumored to be the potential subject of an indictment for ethnic-cleansing crimes against humanity by the U.N.-created Tribunal for the Former Yugoslavia, the same Tribunal will likely eventually be faced with challenges to NATO's conduct as illegal under customary law and the U.N. Charter. It is a reasonably foreseeable consequence of any attempted widespread indictment of the Serbian leadership.
 

The second caveat has to do with the idea that, in a post-Cold War world, the United Nations collective security system would finally function as intended immediately following World War II. As witnessed by arguments over humanitarian intervention (and the very fact that the Kosovo conflict is a NATO operation rather than a Security Council-inspired operation), there still are serious divisions in the international community concerning both what is the substantive law concerning the use of armed force and its enforcement mechanisms.
 

The third caveat concerns the proliferation of tribunals charged with trying war crimes and crimes against humanity, which theoretically might establish more consensus on the law (but may wind up only exacerbating the differences). The U.N. Security Council created tribunals for Rwanda and the former Yugoslavia, while the more general 1998 Rome Treaty attempts to establish a permanent international criminal court with jurisdiction over matters such as crimes against humanity and war crimes. Tellingly, the Rome Treaty admitted that there was no agreement on substantive law in areas such as aggression since it contemplates further attempts to reach agreement on its definition. The United States is actively opposing the Rome Treaty, raising doubts whether a sufficient number of States will ratify the treaty to enable it to come into force. The problem with tribunals articulating "rules" is noted above in conjunction with NATO operations against Serbia (the Kosovo conflict) and potential indictments at the Tribunal for the Former Yugoslavia. If States are still in basic disagreement about the rules' content, the conflict may be concentrated by tribunal actions. It already happened with the International Court of Justice's Nicaragua Case.