The current conflict locations aren't near the headwaters of the Ganges, which are mostly on India's side of the Himalayas. They are near the headwaters for the Indus, but most of that flows to Pakistan.
I think war can still go on between nuclear armed nations - Tradional naval war happens in a localized region whereas the nuke option with current ICBMs is a complete and utter destruction of the country. Imagine 200 ICMBs landing in the US or China. So, I think this would be the last resort and not the first.
Nuclear deterrance works when one party is actually suicidal and weak (North Korea), because if they smell blood, it will be serious. It doesn't work when both states are on equal footing - neither one is going to push the red button when there are other options to solve the disputes such as traditional skirmishes.
Nope, there will be no great power wars while MAD still exists (and it does between china and the US).
At best, you will get some kind of military skirmish before they decide to pull out the nukes. There will likely be threats of nuclear exchange which lead to a cease fire. If there is no cease fire, than God help us all.
But no, two nuclear armed states are not going to fight a large scale conventional war. Partly this is because the US would spank China in a conventional war.
Not sure that the US would spank China in a conventional war. Offshore, maybe (I'm not even sure of that one). Air war, maybe (not sure about that one either). But China's not going to invade the US, and the US isn't going to invade China. That leaves a conventional war a standoff on the bottom line.
Invading is only needed if you want to control the place. A bombing/napalm campaign like the US did in the Korean and Vietnam wars, applied to the most important and populous regions of the country, would cripple the country for decades.
Unsure what their reaction would be. Probably not with nukes against the US, but slagging their allies in Asia is a plausible option, depending on their behavior before and after the event. The US might not be able to protect their allies in Asia from such retaliation.
I do wonder what will happen when we arrive at a point in the future where a country has developed perfect ICBM intercept technology. Of course there is still the submarine and bomber approach as well but they can’t as easily be dialed up in literal minutes.
If just one country has it, it will be safe from nuclear threats until the others catch up. However, it might still be vulnerable to conventional invasions. Because perfect ICBM interception doesn't change the equations for countries that are not nuclear and don't have a reliable ally that is.
If all powers have it and ICBMs become useless, WW3 is still possible, even more likely. After all, the Cuba crisis happened right after MAD became plausible and set a precedent that is hopefully followed in the future.
Finally, MAD is just as possible with bombers and cruise missiles, possibly launched by submarines. It's just a lot more expensive and probably less reliable. But if just, say, one or two nukes can reach their intended target, it might be enough to discourage large-scale and/or nuclear wars.
That would depend on what you mean by perfect and how this system would work? If it were to work in the end/reentry phase, I don't see a reason why it shouldn't work against bombers, or ICBMs/cruise missiles launched from submarines also? Either it can fly-swat anything incoming, or it can't.
