When exactly in his career did he sell-out?

He officialy sold out when he made Saving Private Ryan which is a pro military propaganda

Uh, what do you mean by "pro military propaganda"? Do you have something against the military?

preparing the public opinion to 9/11 and the wars to come

No, it did not. World War II had nothing to do with the War in Iraq.

Spielberg is a war monger while George Lucas is a pacifist

a) Spielberg is not a "war monger"
b) Where did you hear that George Lucas was a "pacifist"? How does a "pacifist" direct a movie titled Star Wars? 

Then he went on by producing another military propaganda Band of Brothers

Your hatred of the military is pretty reprehensible. The military fights for the protection of its citizens. People in the military have died for your right to be free.