When enacting foreign policies, governments face a choice between unilateralism, bilateralism and multilateralism. Unilateralism and multilateralism represent different policy approaches to international problems. Arguably, the Bush administration favored bilateralism over multilateralism, or even unilateralism, for similar reasons. They preferred multilateralism, but did not reject unilateralism. The converse of multilateralism is unilateralism, in terms of political philosophy. It has also been applied to opponents of globalism, multilateralism and internationalism. There has been a long debate on the merits of bilateralism versus multilateralism. It supports multilateralism, non-interventionism, free trade and humanitarianism. She advocates "reinvesting in diplomacy" and multilateralism on issues of shared interests with allies. Another challenge in global governance through multilateralism involves national sovereignty. Malaysia is a strong proponent of multilateralism and international cooperation. Canada's commitment to multilateralism has been closely related to peacekeeping efforts. Spaak, a convinced supporter of multilateralism, became internationally famous for his support of international cooperation. Legislation since the mid-20th century represents Canadians' commitment to multilateralism and socioeconomic development. Smart power addresses multilateralism and enhances foreign policy.