Where Nazi soldiers defending freedom? Wait, or are Saddam's soldiers the ones defending freedom? No, they were defending a system. In the first case, Nazi soldiers attempted to impose a system- fascism- on a country with another system- democracy and capitalism- that tried to defend themselves, or in the case of Russia, stalinist socialism (I can't say I prefer Stalin much over Hitler). In the second case, the ones invading and imposing a system are the US army, and the others defend.

Saying "defending freedom" or "liberating" is pure demagogy. Saying "defending american democracy and capitalism" and "imposing american democracy and capitalism" sounds more accurate. Same goes for Al Quaeda, they claim to fight for freedom too, in my opinion they fight for theocracy and fundamentalism. Now, the thing is, yes, american democracy and capitalism allow more freedom than stalinism or theocracy (well, theocracy is a very relative term, you can say it can bring more freedom, but certainly not in the way it is practiced today), yet I highly doubt it is The System of Freedom, because in fact I believe it to be the ultimate alienation.