The economic status of Russia, China and Iran have all decreased drastically since Trump took office.
If we're going to play this game, China's economy was already declining during the Obama years before the Trump tariffs ever came. Those figures don't lie.
The sanctions Obama enacted during the Kiev crisis started the spiral of the ruble.
Iran politically has gotten stronger, as they've become the #1 target for Trump to attack. That gives them way more credibility as a threat than they had before he decertified the deal.
China has expanded their territory on the unclaimed islands, and now Duterte of the Philippines is their best friend. We see how much they're trying to suppress the Hong Kong protests indirectly.
North Korea has been given actual photo ops and credibility on the world stage despite all of Trump's play nice and "tough talk".
Saudi Arabia basically does whatever they want because as long as they buy rooms at Trump hotel, he's going to do things like declare a national emergency to bypass Congress to sell them arms. Also they murdered a US journalist and our Tough Talk POTUS didn't do a damn thing about it.
As for Russia, I don't have to explain why their position has improved. They basically are being given free reign by Trump to laugh at us and Trump will defend anything they do.
I highly recommend reading this book
https://en.m.wikipedia.org/wiki/Foundations_of_Geopolitics
Everything Trump is doing right now, is pretty much textbook out of that playbook.