Is USA in the Bible during the Tribulation?

Is. 49.12 says "these will come from far away, from the north and from the west." USA is definitely from the west.

Who are the Muslims? What role do they play?

"I will contend with him that contendeth with thee [Israel], and I will save thy children. 26 And I will feed them that oppress thee with their own flesh; and they shall be drunken with their own blood, as with sweet wine: and all flesh shall know that I the LORD [am] thy Saviour and thy Redeemer, the mighty One of Jacob" (Is. 49.25,26).

It looks like everyone, usa included, is gathering together against the Lord's Anointed (Jesus and His followers).