I think AI has evolved to the point that the unmanned wingman will become the rule, not the exception. Did you all see the report last week of the AI aircraft versus a manned fighter? The AI aircraft won every battle. I also see autonomous subs playing a huge role in ASW warfare. And I foresee lasers becoming a prominent weapon system, especially for anti-air and anti-missile defenses, as the speed of light is faster than hypersonic. And yes, hypersonic will Become a prominent technology. The problem with hypersonic is that a false launch detection will be very dangerous, as the decision to respond to a perceived attack will be a window of 2-3 minutes, unlike the 10-15 the big powers have now.
As for the nuclear option, don’t fool yourselves, they are still on the table. I think it’s pretty much common knowledge nowadays that all those fighter bombers sitting on alert pads during the Cold War had tactical nuke ordinance loaded, as did the Soviets. If the balloon went up it was going nuke from day one. The Russian doctrine saw tactical nukes as just bigger artillery and that’s how they planned to use it. NATO would have had no choice but to do the same. I think that logic might hold true in the present day.
Cyberwarfare is going to be huge. Look st STUXNET, look at ransomware, and then think how you would use something like that strategically. The possibilities are endless.
GPS is vulnerable, but so are our potential adversaries' constellations as well. So space will be a vital battlefield because he who owns the high ground wins.
As for chemical weapons, I read in the book “Operation Paperclip” that the western allies captured a German production facility that had 180000 tons of nerve gas. That would have been enough to kill every soldier, man, woman, and child in England, Scotland, and Wales with enough left over to kill off another country or two. But Hitler forbade its use for the reason previously given. I see lesser countries using it against neighbors and maybe against a superpower. The problem with using chemicals against a big power is that they are “weapons of mass destruction” and a big power will respond in kind.
And last but not least, look at COVID? It’s a naturally occurring virus, but I think everyone here can recognize the potential for germ/virus warfare. It’s chilling to think about, but not beyond the realm of possibility.