International Law and the Preemptive Use of Force Against Iraq [Updated April 11, 2003] [open pdf - 42KB]
"On March 19, 2003, the United States, aided by Great Britain and Australia, initiated a military invasion of Iraq. Both the U.S. and Great Britain contended that they had sufficient legal authority to use force against Iraq pursuant to Security Council resolutions adopted in 1990 and 1991. But President Bush also contended that, given the 'nature and type of threat posed by Iraq,' the U.S. had a legal right to use force 'in the exercise of its inherent right of self defense, recognized in Article 51 of the UN Charter.' Given that the U.S. had not previously been attacked by Iraq, that contention raised questions about the permissible scope of the preemptive use of force under international law. This report examines that issue as it has developed in customary international law and under the United Nations Charter. It will be updated as events warrant. (For historical information on the preemptive use of force by the U.S., see CRS Report RS21311, 'U.S. Use of Preemptive Military Force'.)"
CRS Report for Congress, RS21314