George W. Bush held the office of President of the United States of America when the September 11 terrorism acts were carried out in 2001. Osama bin Laden, a militant Saudi Arabian muslim, soon claimed responsibility for the act. He had been forced to leave Sudan, after attacks on a US embassy, and the USS Cole, and sought haven with the Taliban in Afghanistan.
The US government demanded that the Taliban hand Osama bin Laden unconditionally over, but when they refused, the US military invaded the country to capture the heads of the terrorist organisation, al-Qaeda, which Osama was said to lead. The initial invasion appeared to be a success, and coalition forces soon gained control of Kabul. Soon, however, it became apparent that the country was not quite won yet; warlords swept in to fill the power void, and the Taliban regrouped. Eight years later, there are few prospects for peace in that war-torn country.
While the Bush administration was eager to explain that its "War on Terror" was in no way a war on Islam, not all were convinced. Calling the incursion into Afghanistan a "crusade" was a sore spot for some Muslims and particularly after the second US invasion of Iraq, the relationship between the US and the "Muslim world" became a sensitive issue.
However, Bush also publicly stated that he believed that Muslims have no barriers to entry into Heaven that are not also faced by Christians, and that Islam was as acceptable a path to God as Christianity.