The US does kind of do this through its national labs. They just don't have the thriller-esque story of the Manhattan project to romanticize things and aren't wasting their intellect on maximizing doomscrolling.

Manhattan projects don't really work unless you feel that you are under existential threat.

Israelis perpetually do.

Look at all the protests going on at places like Google. There's a segment of the population, especially in tech, that is irrationally anti-military. Somehow people think if we all held hands and sang Kumbaya, all the evil wars would stop, as if people like Vladimir Putin didn't exist.

Think the idea here is that the US supplies the weapons for those wars and we should stop doing that.

Which is a clueless idea, but it's an idea. The US refusing to supply weapons would have, if anything, encouraged Putin to be even more genocidal.