Just because the US doesn't invade by name, doesn't mean they aren't involved, often at a fundamental level. Look a Chile; Nixon gave the orders and supplied to weapons and CIA support behind the coup that brought Pinochet into power. 3,000 people were killed and 200,000 were exiled during his reign. The US has always tried to get its way by pulling strings behind the curtain, where public awareness is absent.

http://en.wikipedia.org/wiki/Covert_United_States_foreign_re...

Also take a look at East Timor.

http://www2.gwu.edu/~nsarchiv/NSAEBB/NSAEBB176/

U.S. support was fundamental to a conflict that killed 100-180,000 Timorese. But not many are aware of this.