Not quite how it works.
If Germany won ww2, there's nothing to say the USA would exist at all today.
Fighting wars abroad is much cheaper than fighting them at home.
The UN & those who participate have a mandate that territory cannot be taken by force. This collective agreement uses allies to enforce. It give the majority of power to the allies, which results in peace.
Russia and China are out to take territory by force. Any "peace" in ukraine is temporary without a change in leadership. Trump is more temporary than Putin or Jinpin.
The whole world would be buying US arms after seeing their effectiveness in Ukraine, that gives the US such an advantage, now Europe are going to produce a shitload more of their own, because they can't trust the US.
So while Russia and China are trying to remove the USD with mbridge as the default currency, a heap more countries look at the USD with increased liability.
I don't know why the maths is so hard.
This isn't a win for the US at any level.