Pakistan was founded as a Muslim state, and it is not a reasonable expectation for it to work against Islam in Afghanistan by supporting the heretical idea of secular government.
Not accurate. Pakistan was founded as a secular nation. Their motivations in Afghanistan are all about power and control. Pakistan had militarily supported the Taliban against the Northern Alliance in the 90s, and so now that the Northern Alliance runs the government they ally themselves with India instead of Pakistan.
The only reason Islamabad gave the US the time of day in the past was to obtain arms to use against its mortal enemy India which was buddies with the Soviets during the Cold War.
The US came to India first. They wanted to be able to put missiles in India aimed at the Soviets. But India wanted to be neutral. Pakistan saw this and decided to ally with the US for money and arms to use against India. After China invaded India and gifted land to Pakistan, India gave up on neutrality and joined with the Soviets.
India would be wise to make buddies with the US after the US-Pak relationship collapses. If it comes to war, US assets could help India take out Pak nukes which are a menace to civilization.
It's never that simple. There have been several wars. And India always wins. Pakistan wants Kashmir because that's where the water is. There's not enough to go around so Indian dams cause the Pakistani rivers to run dry. They are so desperate for it that they constantly send their soldiers over the border posing as Kashmiri freedom fighters to fight and die. Like North Korea they are a doomed nation with nothing left to use. So they continue to terrorize out of spite. Even before both sides had deployed nuclear weapons, India had always stopped short of invading Pakistan because they see no use in trying to occupy it.