In less than five years, the United States has participated in three major military campaigns, each an apparent departure from then-prevailing use-of-force paradigms. NATO conducted the first, Operation Allied Force, in 1999, to end abuse of the Kosovar Albanians by ethnic Serbs of the Yugoslav security forces and to force President Slobodan Milosovic back to the negotiating table after his breach of the Rambouillet accords. (1) Although humanitarian interventions had been mounted with United Nations Security Council approval (sometimes ex post facto) in the past, (2) this was the first conducted by "normatively mature" states without a mandate and in the face of opposition from a permanent Council member, Russia. (3)
Two years later, on September 11, al Qaeda operatives hijacked four commercial aircraft, flying two into the World Trade Center and one into the Pentagon. The fourth crashed in Pennsylvania after passengers courageously attempted to seize control from the terrorists. Nearly 3,000 individuals perished in the attacks. (4) The U.S. response was swill and aggressive. In less than a month, U.S. and British armed forces launched Operation Enduring Freedom against al Qaeda targets in Afghanistan, and against the Taliban, the de facto rulers of most of the country.
In terms of international law, Enduring Freedom charted new ground. Cooperative law enforcement was the generally accepted response paradigm for terrorism at the time of the September 11 attacks. The United States, however, treated the attacks as acts of war and replied militarily. (5) Moreover, not only did the United States strike al Qaeda targets, but it also attacked a regime that, although offering sanctuary to al Qaeda, had not provided the level of support theretofore legally necessary to justify military action against a State sponsor.
While operations continued in Afghanistan, attention turned to Iraq, which was in material breach of a number of United Nations Security Council resolutions regarding weapons of mass destruction and terrorism. The United States, inter alia, referred the matter to the Security Council, which, in November 2002, condemned Iraqi breaches, mandated a new inspection regime, and warned Iraq of "serious consequences" in the event of non-compliance. (6) When United Nations weapons inspectors concluded that Iraq was in non compliance, (7) the United States sought a Council use-of-force mandate. Although unsuccessful in securing one, (8) on 19 March 2003, the United States led a "coalition of the willing" in an invasion of Iraq. (9)
Formally, the legal justification for the attack relied on a series of Security Council resolutions stretching back over a decade to the first Gulf War, (10) the most important being Resolutions 678 (the use-of-force mandate, 1990) (11) and 687 (the cease-fire, 1991). (12) In addition to the official legalistic explanation, myriad other justifications surfaced from both Administration and academic sources: preemption of weapons of mass destruction proliferation, preemption of terrorism, humanitarian intervention, and regime change numbered among the most visible. (13) Yet again, the preexisting normative envelope appears to have been pushed. In particular, the United States presented the international community with an argument that it was appropriate for individual States to force Iraq into compliance with demands issued by a body that could not itself agree on the need for military action.
Since September 11, the United States and its coalition partners have also been conducting a "global war on terrorism" (GWOT). An illustrative GWOT operation occurred in 2002 when a CIA-controlled Predator drone attacked a car carrying Qaed Senyan al-Harthi, al Qaeda's senior operative in Yemen. (14) Consider the unique nature of that use of force. U.S. intelligence officers used military equipment to conduct a deadly attack in a country in which no armed conflict was underway, all with the cooperation of that country's intelligence service. …