Cross Israel off the list, realistically it isn't defendable in the short run, and I doubt that the US really wants to send it's kids there to fight a definitely losing cause. Go back when it's over and re-establish the State.
Uzbekistan, Azarbaijan, basically all the Stans will be on the wrong side, Indonesia, Malaysia also will go the wrong way in the beginning, Singapore is insignificant, and has it's own problems in that it is mostly Chinese in a Malayan Moslem part of the world.
China will try and re-establish it's former perceived hegemony from the glory days, in other words most of eastern Asia, including Siberia, central Asian countries, southeast Asia, Korean Peninsula, and try for Japan.
Europe and Russia and the Americas, Australia and New Zealand will be on the other side. Russia will basically shrink to geographically European boundaries.
3 basic groups, the Christian countries, the Moslem Countries and the Chinese Empire. Northern and Central Africa will be written off except for those areas that have valuable resources (Niger - Uranium, etc) The rest of the world will have other things to do than to fight over a continent being depopulated by Aids and resultant famines. South Africa will side with the West
Aint gonna be pretty.
Can it be prevented? Need to have leadership that will prevent the Moslem world from becoming radicalized and expansive, and put China back into bounds (Not Kerry and his ilk)