We're too stupid to use that leverage against us. We could easily arm India to the point that Pakistan would be outmatched. Or, we could just pull the plug and let the area resettle to normal levels. Pakistan won't be able to maintain their military without us.
Afghanistan is the key. If we need to be there, we need to endure whatever abuse Pakistan throws at us to keep the supply route open. If we don't need to be there, we can pull out and leave Pakistan to the wolves. Until we make that decision, we're stuck pumping billions into them and getting slapped in the face for it.
It lasted less than two weeks. The Pakistan army involved in the fight outnumbered the Indian Army and Bengali rebels by a ratio of about 2.4 to 1. When it was over, about 1500 Indian and rebel soldiers were dead compared to over 8000 Pakis. Bangladesh was independent.
Remember, this was only 23 years after the partition of Pakistan and India when the countries were pretty evenly matched. In the 40 years since, India has made great advances and Pakistan has become even a worse third world sh*thole than it was then.
Do the math and tell me how long Pakistan would last in a similar one on one match today.