The break with the Communists and the development of a Red military problem were continuing forces driving the Nationalists to the Right, where opportunists and reactionaries of all categories welcomed them. They were also drawn to the Left--by the social revolution which had carried them to power and by the need of agrarian and labor reform. Central to the very continuance of the government, however, was the military power of the Nationalist armies led by Chiang K'ai-shek. Without the armed force to implement their decisions the Nationalists would have been compelled to let their endeavors subside into subterranean defeat. To the considerations of Right, Left, and armed force were added responsibilities incident to government. The Kuomintang in its governing phase, therefore, plotted its course with reference to three points: doctrinal consistency, military necessity, governmental responsibility.[1] As an ideologically constituent movement, how did Nationalism use its power? The Nationalists in power had to find their way through class alignments, inert and meaningless oppositions, the rancor of the Left, the contempt of the established monarchist Right. Personalities in conflict, cliques forming and disbanding, factions denied overt expression--these lay behind the pressure politics of the intra-Party contest for the control of policy conducted on a thin and novel constitutional plane. The written formulas guiding the struggle for power were supplemented by the bodies of unwritten practice which had developed in the years of the Republic. There were appropriate forms for extraconstitutional action, just as for constitutional. It was the outstanding contribution of the Kuomintang to modern Chinese government that it kept its internal conflicts within its own constitutional framework, and did so more successfully than any other movement in modern China.