India is a economic powerhouse —Pakistan is not.
India would immediately be supported by the entire West. The Arabs (mostly Saudi Arabia) would be under pressure by West not to aid Pakistan directly.
China would almost certainly aid Pakistan as they are strategic partners and anything that weakens India is a plus for China in this geopolitical chess game, but China is not an energy giant. It would have to use its own energy imports to feed Pakistan on top of financial and military aid.
This opens up the question how much can China aid Pakistan on its own? NATO aid total to Ukraine has been 100B+ in just a year. China on its own would have a hard time sustaining such a drain on its coffers without sacrificing at home. Which will then open up China to domestic unrest as its population questions why they need to subsidize Pakistan’s war. In the West their populations largely accept that their countries are imperialist war machines. In Iran, Russia, and China the populations are quick to question why they should be paying for someone else’s war. Not so much in the West.
This will also open China up to getting sanction by the West for aiding Pakistan. Which will likely lead to a WW3 or at the very least set the showdown for the start of WW3 over Taiwan.
This is why war between India and Pakistan is unlikely. Because the definition of “winning” is too hard to define (is it Kashmir? Is it half of Pakistan in case of India invading?) and the second and third order effects are so hard to predict. Add in nuclear weapon deterrence and it makes this whole thing a headache for war planners.
This is why neither party has gone beyond border skirmishes for decades.
One cannot make a general statement about the India-Pakistan conflict without considering the specific circumstances under which they are fighting. If India is the aggressor, it would be difficult for the USA to openly support India. Moreover, it is not in the USA's interest for India to dominate Pakistan and claim the entire Indian subcontinent. The West also benefits from this conflict in the region.
It is possible that Pakistan may work with Afghanistan or the Taliban to stop India, but this could potentially lead to Pakistan being infiltrated by Islamist groups, thus strengthening their position. If Pakistan were to be isolated, it may take such a step. Saudi Arabia could support Pakistan, and the USA could do limited things about it unless it was specifically in Pakistan's interest.
However, all of this is subject to a conventional conflict. It would not be the first time that a larger power failed to defeat a weaker one. India would only have the West's support if Pakistan had already become a pariah state and was diplomatically isolated.
Let's assume the following scenario:
- Extremists overthrow the government in Pakistan
- Terrorist attacks take place on Indian territory, possibly with chemical weapons
- Pakistan allies itself with terrorist organizations or gives them shelter to act against India
- An extremist leader in Pakistan incites against India
- Pakistan breaks off all relations with the West and builds up the West as an enemy
- The US embassy is attacked in Pakistan
- Liberal forces are persecuted and tortured, and secular ideology is completely eradicated. Sharia law is introduced as a result of the Islamist coup, similar to the Taliban.
- Religious minorities such as the Ahmadiya or Shiites are ethnically persecuted and suffer genocide as a result of the new government.
In such a case, the country would be so far removed from the global community that perhaps only China would support Pakistan out of its own interest. Saudi Arabia would support Pakistan, but only secretly.
It's important to note that this scenario is unlikely. Nevertheless, it is possible that in another scenario in India, a right-wing Hindu party comes to power, which then persecutes Muslims and possibly triggers a large-scale exodus of millions due to genocide. India could also talk about conquering Pakistan, and sporadic air strikes or drone attacks on Pakistan could take place (similar to Israel in Syria).
as a result, pakistan would launch a limited act of defense with the goal of creating a buffer zone in india or securing the muslim areas in northern india, or it could also preemptively defend against india. Pakistan remains passive and India attacks Pakistan with the aim of conquering Pakistan completely.
If a war were to break out in this context, it would be difficult for the West to support India in such a way that it would lose an important ally.
