This article emphasizes how individual decision-makers and their perceptions of windows of opportunity can play a decisive role for major changes in the foreign policy of states by conducting two case studies. The first case is the change that occurred in Denmark’s foreign policy in August 1990 when its government dispatched a warship to the Persian Gulf to participate in the monitoring of the United Nations sanctions against Iraq. The second case is the change that occurred in Australia’s foreign policy in April–May 2003 when its government abandoned Australia’s long-standing “hands-off” approach toward Solomon Islands by leading a multinational military intervention. The article demonstrates that individual decision-makers, with a long-standing desire to change policy, perceived structural changes as a window of opportunity for initiating the desired policy changes. The article concludes that, had it not been for these particular individuals, and their perceptions of the world around them, events would most likely have unfolded in a different way