If this was real and indeed did happen, all the countries involved would stop shipping oil and natural gas to the US, no oil no tank. Also Canada would stop supplying electricity to the US, sending the US power grid into a cascade failure. Her majesty Queen Elizabeth the second (or whoever the monarch is at the time) would use Canada as a staging area for the invasion force. that being said your enemy would have a land base for there troops and would come in from all sides with overwhelming force, Yes i said overwhelming force. With that many militaries co-operating the US military could not mount a defense against a forces that sizes. the US will have too options... Surrender or Global Thermonuclear War(F*** the Earth up for everyone).
Just my $0.02
I would love to come to this, but i can't
