High Quality Content by WIKIPEDIA articles! The 2003 invasion of Iraq was led by the United States, alongside the United Kingdom and smaller contingents from Australia, Denmark, and Poland. Four countries participated with troops during the initial invasion phase, which lasted from March 20 to May 1. These were the United States (248,000), United Kingdom (45,000), Australia (2,000), and Poland (194). 36 other countries were involved in its aftermath. The invasion marked the beginning of the current Iraq War. In preparation for the invasion, 100,000 US troops were assembled in Kuwait by February 18. The United States supplied the vast majority of the invading forces, but also received support from Kurdish irregulars in Iraqi Kurdistan. According to then President of the United States, George W. Bush and then Prime Minister of the United Kingdom, Tony Blair, the reasons for the invasion were "to disarm Iraq of weapons of mass destruction (WMD), to end Saddam Hussein's support for terrorism, and to free the Iraqi people."