In the videos above, Mark Steel examines the Russian Revolution. It is clear that a revolution happens when enough people stop following orders from the elites in the current structure of society and start standing in solidarity with a new order.
Judging the ultimate results of revolutions, like the Russian is difficult, because invariably the new government is terrorized by foreign intervention. This terror has the effect of concentrating power within the revolutionary government, with a strong possibility of bringing a small group to near dictatorial power which they will seldom relinquish. This is why the American revolution is more of the exception rather than the rule.