I dont think so that its being protected by US anymore, China may be more.
Right now, for at least another few months, still is. The US still needs to completely evacuate Afganistan, plus they need to maintain some presence. Dunno about the long term presence, but at least for a few months more.
China's protection doesn't matter as much. If the US is still protecting Pak a decade down the line, it won't matter as much either. We will be our own side by then.
Pakistan is being protected by our own inability.
Not at all. Pakistan would have ceased to exist in 1986. The US protected them that time too, especially because the SU was going down the drain. Brasstacks wasn't just some exercise.