Nope, the war is underway. Take the battle to the enemy and stay on the offense
I'm not talking about the wars in Iraq and Afghanistan. I'm addressing the thread's original hypothetical of "banning Islam" in the US. Sure, there may be a fine line between "ideological" war and actual, physical war. Any Muslim known to view Islam itself as warfare should obviously be watched closely. Very closely. No argument there.
Still, "misguided believer" is not the same as "aggressor." There have been no attacks on US soil after 9/11/01 NOT because we "banned Islam," but because we're vigilantly pursuing suspected terrorists and their supporters. There is no need to physically "take the battle" to non-combatants.