The parties are kicking a lot of dirt on each other right now. Trying to provoke the other, or prove their manhood for their constituents back home. The Indians are inclined to go, the Pakis are doing their best to dare them to cross the line.
The leftist paradigm allows the weaker Pakis to attack India without penalty, while India must show "restraint". India appears well past restraint at this stage. Add to that the muslim 'humiliation' issue, so that the Pakis feel obligated to respond to the Indian build-up. India attacks conventionally due to some provocation, Pakistan respond conventionally, but is soon overwhelmed in the air and at sea. Some Paki field commander, about to be overrun, resorts to nukes (Paki C&C is notoriously bad - Musharraf claims he has no control, doesn't know where the nukes are. If they're in the field as
reported, even if under "loyal" commanders, their security is significantly at risk). India responds in kind, heavily. Total elapsed time: 3-5 minutes. The World's Shortest and Deadliest War.
If the Pakis simply backed away from the border and put away their toys, world pressure on India to do likewise would be impossible to ignore. However, that would be '
humiliating' to the Pakis ( It's a Muslim Thing, You Wouldn't Understand
© ), so it doesn't seem likely. The US could put its troops in harms way. That would stop the Indis, but not the Paki terrorists. If India pulls back, the Paki fundamentalists would see that as a sign of victory and redouble their efforts. A "Mexican Standoff" of sorts.
Jihadis in Kashmir are the wildcard, no matter how many conversations occur between Washington, New Delhi and Islamabad, If the terrorists cannot be contained by Pakistan (mid-management seems reluctant) or blocked by India (unlikely), further attacks in Indian-controlled Kashmir and elsewhere will occur. If sufficiently provocative, they could push New Delhi to act decisively.