Having lived in the United States since 1992 (and attending Brown University) Müller became a naturalized citizen of the United States in early 2004. He then announced he would trial for the US team for the Athens Olympics. He had won all of the preliminary trial races. However, just before the start of the final set of trials, there were a number of high-profile killings of foreigners in Iraq as part of the Iraq War, and Americans were believed to be potential targets for violence at the Olympics by al-Qaeda. Müller pulled out of the trials, saying: