What would happen if Pakistan attacked India with nuclear weapons?

Though on the extremely minor positive side - there would be no more Pakistani based terrorism in the world and India would acquire that irradiated territory which would provide direct access between South, South East, Central and East Asia not to mention to Russia and Europe too which could alleviate India's power supply problems though at that point - what would it matter?.

In these threads different Quora users hypothetically analyzing the chances and probabilities of nuclear encounter between India and Pak

  • This will remain in the realm of higher possibilities
  • Consider it from Pakistan’s perspective. Apparently the core issue is “Kashmir” and relations cannot normalize till there is resolution of Kashmir as per Pakistan’s wishes. Contrast it with the patience and sagacity that China has displayed to resolve Hong Kong or Taiwan. When China’s stated policy itself is at loggerheads with Pakistani approach on similar issues, to expect China to militarily support Pakistan during hostilities would be insane.

For decades India has been working on what is called the Second strike capability – the ability to respond to a nuclear attack. The reason India has been working so hard on navy these days is partly to have a credible second strike.

Given the extent of India’s geography and extent of Pakistan’s capabilities only a fraction of Indian territory would be damaged by the first strike. Pakistan doesn’t have aircraft carriers or nuclear submarines to launch a strong attack on India and has to purely rely on long range missiles, which are fairly inaccurate. Unless Delhi is destroyed, India’s response would have a very swift response. If Delhi is destroyed with no warning, Army has to work on new protocol on the go for taking control.

India’s response would be expectedly brutal. Almost all of Pakistan is easily accessible to Indian bombers [most of population live within 100 miles of Indian border]. This makes things asymmetric. India’s biggest population centers are away from the border in contrast.

India also has a variety of submarine launched missiles like K4 that would start firing from near Karachi. India Inches Closer to Credible Nuclear Triad With K-4 SLBM Test

If Pakistan is proven to be the striker, neither US nor China would come to its help and Indian Navy’s nuclear carriers would have field day launching bombers from the Pakistan’s south while the Air Force would come from the north backing the army’s move from east.

Besides second strike, India is also working to avoid this in the first place:

  1. Indian Ballistic Missile Defence Programme – Since missiles are the only credible vehicles for Pakistani nuclear weapons, India has been working on a BMD for a very long time.
  2. Intelligence: A nuclear attack on India is not good for US or any other power. US as a major weapons provider to Pakistan has a fairly tight control on the data and it is very hard to evade CIA, R&AW and Mossad if you have to assemble a large scale nuclear deployment. They might be able to slip one or two nuclear weapons, but if they are trying to attack India they would have to move dozens of nuclear bombs & that would be noticed.