We can defend ourselves, it's just that the US didn't want a too-powerful Europe until trump. In particular nuclear. They heavily pushed against that.

We'll have to scale this up now but it is not a big problem.

Population collapse is a good thing. We already have too many people in this world, causing environmental and housing issues. We can't keep ever growing as humanity, stabilisation or even a reduction is very good. It'll cause some short term cash flow and elderly care issues but we'll deal with that.

And AI so far is more of a hollow promise and hype. It's not a race, the way America is approaching it it's inevitably going to lead to a bubble collapse.