Like many here, I find India annoying and I sometimes laugh at the anti-India jokes. Perhaps Indians make similar jokes about Chinese.
Nevertheless, let us assume a situation of forced reunification in Taiwan.
Would India blockade China?
Would India bomb China?
Would India send troops to Taiwan?
Now let us ask - would the USA do all of the following?
The answers to these questions tell us the fundamental difference between India and the USA. One country is annoying and frustrating but ultimately tolerable. The other country is malicious and genocidal.
to put it bluntly a million strong Pakistan Armed Forces would seriously curtail Indian decision makers to go full against China