What happened to Hollywood accents?

This trailer is about Germans, in Germany, an uprising of ZeGermanz. So can someone please tell my why Tom Cruise has an Americanese accent? C'mon Charlize Theron dropped her Saffa accent for you Americans, now can you please play fair and even attempt an accent in a movie?Or is it possible that there was an American in the war fighting with zegermanz who tried to bring forth and uprising upon Hitler??