Social revolutions are rapid and violent transformations, carried out by the lower classes, which ultimately transform the political, social, and socioeconomic structures of government (Skocpol, 4). Revolutions do not come easily and are not inevitable. Indeed, some variables must be present at the same time for the current regime to collapse and be replaced by a new system. In the following article I will illustrate how the simultaneous presence of two variables leads to social revolutions in France in October 1789, in Russia in February 1917 and in China in 1949. The first variable describes how wars can cause economic tensions which leads to abandonment of the military, which causes defections. The second variable is the rise of radical ideologies leading to the creation of political parties that mobilize farmers. Note that the 1949 Chinese revolution is chosen as a social revolution because it adheres to Skocpol's definition as a revolution of the lower classes and results in a total transformation of the state, whereas the 1911 revolution does not. I will also discuss why social revolutions did not occur in the negative cases of the Prussian Reformation, the Japanese Meiji Restoration, and Russia in 1905. There are no current theories that explain why, how, and when revolutions occur. The volcanic model states that revolutions occur when people's demands are not met by the state and any frustration of the people will mobilize the masses, resulting in a transformation of the system (Aya, 7). This theory neglects to identify the actors and the connection between mass frustration and social change. It also fails to identify the ultimate spark that motivates people to c...... middle of paper ...... Meiji Restoration, there was no mobilization of the lower people and the Samurai conducted reforms from above. In Russia, radical ideas were present in 1905 and mobilized the peasants, however, the military was present and therefore, since both variables must occur simultaneously, there was no revolution in Russia in 1905. The collapse of the army alone did not it would have caused a revolution. revolution; nor even protests or riots alone. However, it is the combination of the collapse of the army and the uprisings against the state that causes a revolution. The collapse of the state's forces allows insurgencies to become powerful and thus have the opportunity to attack the state when it is at its weakest point. The two variables I discussed show that both variables are needed at the same time for a revolution to occur.