One could argue that since the beginning of the 1980s, the United States has become increasingly influenced by international events and their effects on international diplomacy. The ending of the Cold War, retaining a position as the remaining superpower, and the beginnings of a worldwide war on terror have been important to any study of contemporary US history. When President George W. Bush ordered the invasion of Iraq to overthrow Saddam Hussein in 2003, he took a largely unilateral military action. His stated purpose was to increase US national security. Presidents Clinton and Obama favored more multilateral efforts when intervening in countries such as Kosovo and Libya. Is there a justification for the US to engage in unilateral rather than multilateral military action overseas?