Honestly, I don’t think it will really be a war, I think it will last as long as they try to take Taiwan because short of nukes, China and the US have no way to actually visit widespread damage on the other. If china takes Taiwan, then that’s the end of that. If Taiwan isn’t taken, there’s really nowhere else to continue fighting them, and there’s not nearly enough support for some massive war and naval invasion against China from what I see. It’s going to be a battle for maybe a couple months while they try to take Taiwan, but I don’t see any way it devolves to more than that unless they try supporting North Korea into South Korea, which I think would be unlikely as well