Well, I thought of this brilliant strategy! Because some EU nations are under the NATO, The nations can rebel against the US and the whole entire EU can group together. They can then use UK as a front base where the troops can gather and from UK start their assault from air and sea. Massive shift of Naval weapons from all EU nations moving forward to US from the Atlantic oceans. Scandinavian Countries and the Russia can mobilise their troops to Iceland as a forward base. On the other side of the world China and North Korea prepares to attack. Indian troops can mobilise by sea and air. By Sea from India through Singapore and then to Philippines. Japan and Philippines would be used as a forward base from the Pacific Ocean where a major land and sea assault will take place. Mind you, at this time, the world's 1st, 3rd, and 4th largest army in the world are gathering and moving through air and sea towards USA. Once the outlaying islands of the US have been destroyed, The european side and asian side would start their series of air raid and sea landing simultaneously at the same time. Mexico and the South American countries would force the US troops to move north wards. At the Northern end, The Canadian forces with the help of Russia and Japan have already taken Alaska and are moving down South. This would make an all round attack for the US. By this time, the Combined forces of the world would have penetrated the front line defences and the rest of the war are fought on land in US. Although all citizens in US may have weapons, the combined world forces can be given an order of shooting every person seen holding a weapon. I think through this way, the US can be defeated!