Unless you are looking narrowly at nuke counts, Russia is not a great power. It's economy is propped up by oil and gas, and that's in question going forward, it is inefficient and outside of primary products it doesn't produce much of anything anyone wants. Its military has been exposed as a paper tiger and even the nukes can't be guaranteed to work these days.

China has the economic and manufacturing clout and is building up its military, but outside of the 'Global South' and various needy countries it has little soft power.

The US has stumbled somewhat mostly due to the overreaction to 9/11 and Bush's disastrous presidency, followed by the overcorrection of the Obama and Biden presidencies. But it still has the biggest and most powerful military, and NATO has been shocked out of its long complacency.

What the US has going for it is the possibility of renewal and reinvention, that is its strength and its enduring power. The US will keep on innovating, hopefully also in the political realm, and will retain global leadership. That's assuming that the Trump led Republican nihilist suicide cult doesn't destroy it first.