There was significant opposition to the Iraq War across the world, both before and during the initial 2003 invasion of Iraq by the United States,the United Kingdom and smaller contingents from other nations, and throughout the subsequent occupation. People and groups opposed to the war included the governments of many nations which were not part of the invasion, and significant sections of the populace in those which did. Rationales for opposition included the belief that the war is illegal according to the United Nations Charter, or would contribute to instability both within Iraq and the wider Middle East. Critics also questioned the validity of the war's stated objectives, such as a supposed link between the country's Ba'athist government and the September 11, 2001 attacks on the United States and its possession of weapons of mass destruction "certified" by the Niger uranium forgeries. The latter was claimed by the United States during the run-up to the war, but no such weapons have since been found.