Considering US has technological lead, reserve currency, workaholic culture, giant capital, reserves of raw materials and large population the only country that can challenge US is China.

I have a sneaking suspicion that a lot of the leadership and capability is far more precarious than many believe. Might is actually myth. If you remember it was only a couple years ago that the might of the Russian army was to be feared globally - is it still the case?

Europe should become more self sufficient and less reliant on US so that it can at least defend itself or else it risks being quickly overrun by Russia if it manages to defeat Ukraine.

I suspect this isn't possible, unless Russia are willing to go nuclear. And in that case, we are all screwed globally. Europe isn't quite as unprepared as the the people of the US are led to believe, and when push comes to shove, they will gather. The EU has 450 million people in it - with many willing to push back.