The United States need not be invaded in the traditional sense. All that is required is for a political regime to give up our sovreighnty by way of "International Treaties". Treaties in which the US Senate has no ratification powers, just unilateral signing by the POTUS or Secretary of State. No need to invade, just change the way the game is played. It is the same end result. The "Coalition of other countries" would be the United Nations, many of whom would love to see our military and economic powers reduced to a shambles. Nations such as Russia and China would then be in position to dictate our affairs to us at will via the UN.