Revolutionary Assistance

Looking at the events in Libya, its hard not to reflect on the role that other nations play in affecting the outcome of a revolution.  France was a crucial partner in the US revolution against Britain, and the US, and its NATO allies were crucial in the success in the Libyan revolution.  It is interesting to note that revolutions, while filled with messages of self-determination and other such nationalist fervor seem to be as much the product of global power struggles as internal ones. 

General Lafayette

Looking back at the situation in the US around the 1770's I am amazed at the level of support that we received from France.  One thing that I don't understand is why the French were so keen to help us out!  Gen. La Fayette for example came here to fight on our behalf on his own dime and encouraged the French aristocratic class to contribute to our cause.  What was their perceived benefit?  Was is purely altruistic, or were their other motives?