I think you will find there are no US military bases in Pakistan John Bingham. There maybe some CIA dark ops there but Pakistan's military intelligence is quite adept no matter what you hear or read and so that in itself makes it difficult to work in the country. I can tell you about a couple of bases I as at in Afghanistan while I was there and yes the US "may" have used those bases to conduct drone strikes along and inside Pakistan's border in support of operations but it would have had an even more profound effect if US forces had been able to operate from in Pakistan.
Many Taliban and Al Queda operatives used the fact to their advantage and then left a rearguard made up of mainly North African, European, Chechen and Middle East fighters behind to slow the advance of allied military forces. They then used refugee camps in Pakistan along the border to come and go back into Afghanistan as they wanted in a similar fashion as to how they fought against the Russians to the best of my knowledge.

My general thought is China needs a military presence in the Gulf of Thailand so if the South China Sea becomes hostile they have another route around Singapore.

In 4 meters channel depth?