It can last until no one will extend the U.S. government credit. From Richard Solomon at unz.com:
Theoretically—Until the US Empire’s Credit Card Gets Declined
America spends more on its military than all the next ten countries combined.* (* Scientific American). The US can still conjure up trillions of Houdini digital dollars out of thin air without going into free-fall hyperinflation. This allows US chickenhawks to continue playing Napoleon long after others would have packed up their toys and headed home. The neocons dragged out the Afghanistan debacle for over twenty years.
The Ukraine Project porcupine has sharp quills. The US and NATO spent billions training their Azov neo-Nazi battalions and provided them with a Mount Kilimanjaro pile of weapons. You might not like their Stepan Bandera politics, but it’s hard to deny that Azov are tough bastards. Zelensky can also push millions of forced conscription civilians into the giant rotating blades. However, it’s not just the Ukrainian military that Russia needs to contend with.