Since the Quran advocates expansion by force what posture should the USA take?

The Quran clearly states that the Muslim religion must expand thoughout the world and convert everyone to Islam. The Quran makes it clear in its chapters on Jihad that every able Muslim must fight for the Islamic faith and that women and older people must aid these Jihadists when required. The Quran talks about chopping off the heads and fingers of non-believers. Do we sit back and allow the Muslims to take over (in spite of their claims to the contrary) or do we fight back on a united front? Incidentally, the Quran states that a Muslim is not allowed to become close with a Christian or jew because the Muslim will become contaminated. Also once a Muslim, always a Muslim or the person who leaves the religion is marked for death.