America's first conflict was with Islame, the Barbary pirates, first world war broke up the Ottoman empire, the muslim brotherhood was created right after ww1 to reassert the power of islame, there were many muslims who fought with hitler, who obviously wasn't much of a Christian as he didn't do the Will of G-d to bless the chosen ones. The closer we get to the fulfillment of the scripture and the return of Jesus the more the adversary and his anti christian minions will fight, which we are seeing now.