While it is only logical to believe that India will keep its military deterrence level according to its needs and not Pakistan, Same stands true for us however i dont see the logic behind India bringing Pakistan into and everything just for the sake of either blaming Pakistan or perhaps in an attempt to isolate Pakistan which will only prove to be counter productive as far as Indian interests are concerned.
For starters when India says we have a mechanism for discussing bilateral issues and rejects any third party involvement, then how come it takes a u-turn and asks saudies for help?
Saudi Arabia has leverage over Pakistan, has anybody even bothered to stop for a second and think how much leverage does Saudi Arabia really enjoy on Pakistan and specially when PPP is in government, had it be NS and PML(N) one could have argued but not in the current scenario. Besides lets not forget SA will not go beyond its national interests just because India offered large scale Indian investment.
Here Two things come in mind:
1) what kind of investement and is saudi arabia really in need of such investment by India specially when there are others to fill in the gap?
2) Dont forget Pakistan provides SaudiArabia with both defence and nuclear shield, does India come anywhere near or can compensate even remotely once Saudiarabia alienates Pakistan?
The idea of isolating Pakistan has never worked in the past, nor will it ever work in the future, India should better accept this reality that Pakistan has its own importence at the world stage and any attempt by India to isolate Pakistan or declare it as a failed and terrorist state will only be counter productive to Indias own interest in the region as Pakistan too will do the same to check mate India as we have seen lately in the Afghanistan theatre.
This is my personal opinion, feel free to disagree.