In a conventional conflict the last thing the Soviets want to do is to bring China in. In the 1980s Pakistan is not going to get too actively involved on its own, the USA may stage recon missions and perhaps special forces activity out of Pakistan, use Pakistan for emergency landings etc but no more. Yhe USA does better with this level of involvement, and will probably tell Pakistan that if they start something with India the US can't resupply them. Similarly the Soviets can't spare anything to resupply India so while both sides will glare at each other, maybe even border incidents absent some tragic error they won't go at each other. The countries of South Asia/SE Asia will do everything they can to stay neutral as long as possible. Similarly South and Central America - they may tilt, but no commitment until they see a winner. Picking the losing side, even if it does not have immediate military consequences, will have major consequences postwar. While firing off a few nukes at a neutral would be enough to put them out of the game, doing so with conventional forces would take a l