If you chose to launch a full scale strike, you'd end up de-fanged forever. Pakistan has options.
1. We have Chinese warships stationed in Gwadar. The Russians stopped you bombing Syria, there is no reason the Chinese can't stop you attacking Pakistan.
2. We have the capability of targeting your carrier groups. We can launch cruise missiles from the air, from the ground and from sea (including subs). Anything in the Arabian sea/Indian ocean we can target. Using submarines we could potentially target fleets in the waters around China too. These are busy routes, you congregate there and it's been done before quite easily in war games.
3. We won't wait to go nuclear. We can't go toe to toe, our only option is to inflict as much damage as we can as quick as we can to make the idea to go to war a bad idea. We'd target US military bases in the Middle east as well as it's allies Israel and India.
If full scale war happens there is no scenario in which Pakistan wins, so our only play is to take down as many people as we can in the process. Having the means to do that and having the balls to do that, means the threshold to "walking the walk" is much higher than any American general or politician will ever accept.
If you mess with us, we'll make sure you have no power left in the region by destroying your allies and you're assets.