I've been putting off starting this thread for a while now, however the beating of war drums has been relentless lately and growing ever louder.
There is no doubt in my mind that the 2020s will see a major war between the US and China, as well as their major allies.
China's aggressive stance is unmistakable and there are several signs, that they are gearing up for war and just waiting for the right opportunity to present itself. As the below retired Australian general points out, they will have to take out US bases in Guam and Japan, before they can have any hope of a successful Amphibious assault on Taiwan.
That would probably draw NATO, the rest of the Western Alliance (Australia, New Zealand, Japan, South Korea, Singapore, possibly the Phillippines, Vietnam and India) into the war, with China's SCO allies (Russia, Iran, Pakistan, North Korea the "Stans") providing at least material and ideological support to Chinese forces. It might be a replay, or a global version of the Korean War, but with China in a much better position vis-a-vis the United States, and that conflict ended in a stalemate.
Note, that China has already threatened the Australian mainland with rocket attacks, which didn't even break the news here. This is as serious a situation in terms of global tensions as I have ever seen.
https://www.youtube.com/watch?v=U-A1rUWRpgY