Imperialistic countries were deeply involved in the events leading to World War 1. The main cause of World War 1 was the conflict between the European great powers over territorial control and economic dominance. The European powers had been competing for colonies in Africa, Asia, and the Middle East for several decades, and this competition had led to increased tensions between them. In addition, the European powers had been building up their military forces in preparation for war, and this had further increased the tensions between them.