This study is an attempt to construct a quantitative link for international regimes with global leadership. The country's willingness to lead in solving global issues as the first mover in the formation of an international regime is measured and characterized by analyzing their ratification behavior in multilateral conventions deposited to the United Nations which shape ‘the rules of the game’ of the global community. For this purpose, a set of quantitative indicators, the Index of Global Leadership Willingness and the Global Support Index, was defined and calculated for each country based on its actual ratification year data for 120 multilateral conventions covering global issues such as peace and security, environment, commerce, communication, intellectual property protection, human rights, and labor. By proposing a framework of global leadership analysis, the study seeks to provide an empirical testing of the transformation of global governance towards cooperation without hegemony paradigm. The paper analyses changes in the leadership willingness indices of selected country groups, such as the G3, G7/8, and G20, over the century and finds that the will to drive the international agenda of these groups of leaders is in decline. Moreover, our study provides evidence to argue that our current world is actually without consistent global leadership across domains of the world affairs. Although several countries still show visible leadership in specific policy domains, such as environment and intellectual property, neither the G7/8 nor the G20 was playing a comparable role to those performed by the G3 a hundred years ago.