I think India should consider acting now, before Pakistan has even more time to prepare itself. I think both sides had better cool their jets before a lot of people get killed for no good reason.
The US is trying very hard to prevent such a war, because the only winner will be terrorist networks. Everyone else loses, including the US.
An Indian win would be akin to France winning against Germany in 1936, had they decided to strike. There are winners and losers in great powers conflicts. In this one, the clear choice in terms of US interests is India. It's a no brainer.