Here's a look at what you need to know about U.N. weapons inspections in Iraq from 1991 to 2007.
Facts: At the end of the 1990-1991 Persian Gulf War, the U.N. passed Security Council Resolution 687 setting the terms for the cease-fire between Iraq and the U.S-led coalition. Section C of the resolution called for the elimination of Iraq's weapons of mass destruction and some ballistic missiles and established the United Nations Special Commission (UNSCOM).
Timeline: April 3, 1991 - The U.N. passes Security Council Resolution 687.
April 6, 1991 - Iraq accepts SCR 687.
April 18, 1991 - Under the terms of SCR 687, Iraq gives a detailed account of its weapons inventory and denies it has a biological weapons program.
June 9, 1991 - UNSCOM begins its first inspection looking for chemical weapons.
June 17, 1991 - The U.N. Security Council passes SCR 699, which reaffirms the authority of UNSCOM and the IAEA to conduct inspections in Iraq.
June 23-28, 1991 - Iraqis fire warning shots at inspectors to prevent them from intercepting vehicles suspected of carrying nuclear equipment.
June 30, 1991 - UNSCOM begins its first missile inspection.
August 2, 1991 - Iraq admits to biological weapons research for "defensive purposes" only.
August 15, 1991 - The Security Council passes SCR 707, demanding that Iraq completely reveal all of its prohibited weapons and weapons programs.
September 6, 1991 - Iraq blocks the use of helicopters by UNSCOM teams.
September 21-30, 1991 - IAEA inspectors discover documents relating to Iraq's nuclear weapons program. Iraqi officials prevent the inspectors from leaving the site for four days.
October 11, 1991 - The U.N. passes SCR 715. It outlines the plans for ongoing monitoring and verification in Iraq. In response, Iraq says that SCR 715 is unlawful and that it's not ready to comply.
March 19, 1992 - Iraq declares that it once possessed 89 missiles and chemical weapons, but destroyed them in the summer of 1991. This unilateral destruction of weapons is a violation of SCR 687.
June 1992 - Iraq delivers its first "Full, Final and Complete Disclosure" on its chemical weapons programs.
July 1992 - UNSCOM destroys some Iraqi chemical weapons and production facilities.
July 6-29, 1992 - Inspectors are prevented from searching the Ministry of Agriculture by Iraqi officials. They stage a 17 day sit-in.
July 5, 1993 - UNSCOM leaves Iraq.
November 26, 1993 - Iraq accepts the terms of SCR 715.
June 1994 - UNSCOM destroys material and equipment relating to chemical weapons production.
October 15, 1994 - SCR 949 passes. The resolution demands that Iraq begin cooperating with UNSCOM and withdraw its troops massed on the border with Kuwait.
March 1995 - Iraq releases its second "Full, Final and Complete Disclosure" of biological and chemical weapons programs.
April 14, 1995 - SCR 986 passes. The resolution allows Iraq to begin exporting oil in exchange for food and medicine.
July 1, 1995 - Iraq admits the existence of its biological weapons program.