Who would win in a war between India and China? Why?

If the escalation leads to a war then two main cases would arise -

1.} If it stays strictly a two side war i.e India and China no one is going to come out victorious and both countries would just end up sabotaging each other in many ways, some territories would be won and lost by both the sides, a lot of casualties would occur on both the sides. And I know many in India and almost everyone in China would want to falsify this claim by stating the 1962 war but I don't think the Chinese would be that naive in estimating the Indian military might.

2.} The other case would be that if the Chinese machinery decides to open multiple fronts of war against India by instigating its proxies i.e Pakistan and as it seems by Nepal's present misadventures Nepal so this war in an instant would turn into a World War, WW3. Now some sceptics who have all their scepticism just turned against India would say no one would want to side with India in this war. So for them I would like them to recall the statement that Israeli PM Benjamin Netanyahu gave when asked would Israel support India in a war effort he without any hesitation said India is like a second home for Jewish people and would support India at any and all cost no matter what. So the supporter count of India goes to 1, then again the simple involvement of China in a war against India is what US would want and it would be just about time when India gives a call for assistance those American M-hawk and Apache Helicopters would be rounding up Chinese forces in the Himalayas and those Aircraft Carriers would round up the South China sea. As for Russia it would want to help Chinese side due to involvement of US on other side but again the sheer history of Russia with India and its own suspicion of Chinese expansionuism would make Russia to attain a neutral opinion about this war( at least by my assessment of Mr. Putin as of now). As for European Union and NATO they follow the US but with the involvement of India against China would give them extra impetus to join the war effort from India's side .

So now you see if the war turns to a multi nation effort it would only yield destruction for China as of now the majority of the world forces are against the Chinese Regime and its bullying. So if China thinks that the criminal mismanagement it has shown in handling of Corona Wuhan Virus can be hidden by it by opening a war front against India it would be the greatest mistake it can make because I can't say surely about other damages but the geographical damages would be severe- Tibet, Hong Kong, Taiwan, Inner Mongolia the list would be long.

Depends on what the war is for.

If China attacks India to capture Arunachal Pradesh, India can mobilise troops in the region and counter China easily in that region. The terrain favours India much more than China and India has been very vigilant in the region.

If the war is to conquer the capitals of the two nations, that’ll be a stalemate.

I can copy paste all the military stats in which China is far ahead of India. But there is a reason why India China have never been at war except in 1962 in the long history i.e. Himalayas. Its so difficult terrain for movement of troops and weapons that neither nation can cross it easily.

China ranks #3 in Global Fire Power index while India ranks #4. It is enough to say that neither of the two nations have weak military and are easily capable of defending their homeland. Both nations are nuclear powered. Both nations can now attack every corner of each other with ICBMs. Both nations have equal number of aircraft carriers. China does dominate in the airforce category but that’s just not enough to defeat India. India too has measures for counter-attack.

Now coming to the question, can India win against China? No

To conquer China, India needs to capture Beijing which is far away from Indian territory. Indian army will need to travel through the uninhabitable region of Tibet even if they manage to cross the international border and geographical border of Himalayas.

China dominates in submarines and that makes it very difficult for Indian navy to enter the East China Sea or South China Sea from where it can target the main cities of China. Indian navy dominates the Indian ocean and the Bay of Bengal which makes it very tough for Chinese navy to attack Indian coastal cities.

Have a look at the population density of the two nations and see where India needs to hit hard to defeat China.

Its next to impossible for even USA navy to defeat China in the region so you can cut some slack for India.

Before I answer this question, I would like to mention that I am an Indian.

Let's get into this hypothetical situation, assume that China and India declare war against each other.

1. Ground Invasion - The most important battle will be fought on the ground and it will be on India - China border. I am attaching a map below

In order to win any battle by the army, they must have very strong supply lines. As you can see in the above map, more than 95% of the Indian border with China is not actually with China, but with the disputed territory of Tibet. All supplies either need to come through air or roads. If you are bringing it via road then I doubt that Tibetians will turn hostile to seek the opportunity to get upper hand over Chinese armed forces to seek independence. Now, on the other hand, India has no such problems for supplies. Apart from that, I would also like to mention that India gave permission to run the government in exile for Tibet in Dharamsala. India will definitely convince Tibetian population to harass the Chinese army.

The second thing is the 1962 experience. As you know that in 1962 India lost to China, but at the same time, China also knows what happened in the Battle Of Rezang La(120 men defended this post till the last man alive, and ended up killing 1300 Chinese troops. Despite they were poorly equipped).

2. Air Invasion - When it comes to air forces, this is a very tricky business. Both China and India are well-industralised countries, China is more I would say. Both have developed meaningful weapons to achieve their strategic goals. For example, India has invested a good amount of money and time into missiles. Reason being china will have to protect lots of its infrastructure. But at the same time, China has acquired S-400 SAM(Surface To Air Missile) which is a top-notch defense system available in the world as of now. I personally don't believe that both countries will risk their expensive assets/equipment. Therefore, this war will be fought with limited resources as far as air invasion is concerned. And it will be the same case for a naval battle.

Now, many people will argue about numbers superiority of defense equipment on paper, but that is less relevant in today's world. Let's take the example of Yom Kippur war in Sinai peninsula between Egypt and Isreal. Egyptians used Sagger anti-tank guided missile which knocked down more than 800 tanks and combat vehicles. Below is the photo attached,

All I want to say is that number superiority is definitely plus point but that is on paper, the reality could be different.

So, the final verdict is that India has more chance of winning a conventional war against China. China and India are both reasonable countries so nuclear weapons won't be coming into the picture.

There is no India vs China. This isn't a one on one boxing match. India will have allies while China has very few.