No one can attack America. It's a non starter. China cant even invaded Taiwan. Russia barely has the ability to project power beyond its borders. North Korea could fuck us up more than anyone but after a couple hours it would be over for them and it would be isolated to the korean peninsula. OP who would declare war on us? why? How? Who would we start a fight with now? The window to attack Iran is gone. NK isnt worth attacking because of the damage they would do to South Koreas civilians. Picking a fight with russia would lead to nuclear armageddon, and if you started that why would bother to tell americans to come home?