I think improved Sino-Pakistani cooperation is one vital aspect of this puzzle. I believe 1962 was a huge wasted opportunity (due to the pro-US policies of Ayub Khan), but was certainly not the last opportunity.
Unfortunately most of that coordination is happening behind closed doors, so can't be a part of our discussion.
Modi is going to make the same mistake that Nehru did, of overstretching himself. The question is, when Modi inevitably makes that one big mistake (Forward policy 2.0), will we be there to catch him? And how will we deal with the aftermath.
Modi's tendencies are directed at Indian Muslims, he has no such leverage over Chinese or Pakistani citizens, and both countries are very much able to pay him back in kind. As we have seen during the last Pakistan-India border incident over the LOC, with Modi declaring "We taught them a lesson"... only for artillery fire to resume the next day.
In fact we have seen Modi fall flat on his face (what we call 仆街 in Cantonese) twice already. First with the so-called "Chinese incursion" during Xi Jinping's visit to India, which India tried to pass off as some disconnect between the CPC and the PLA, which any Chinese person knows is pure BS. Xi Jinping has consolidated his power base in the CPC and the PLA to an extent that has not been seen in the last few decades, just check for the name Xu Caihou to see an example.
The second was with his claim to have "taught a lesson" to Pakistan, only to have firing resume the next day. He is stretching the limits of his capabilities, and when he finds out that returning India to 8%+ growth is impossible, he will have to find another way to consolidate his political capital. This could turn into a Hitler-like (or Modi-like) situation, and we know how that turned out.
Luckily for us, China and Pakistan combined are vastly more powerful than India, by multiple times. Modi's foolishness could turn into a huge opportunity to solve the border issue, once and for all.
War is of course the worst case scenario, but Indian policy may leave us with no choice, like it did with the Forward Policy. And we must be prepared for a repeat of the same.