The U.S. Federal government is seriously bought. Most state governments are pretty bought. Some local governments are rather democratic, owned by their citizens. That’s a reasonable argument for handling international policy at the local level.
Possible paths forward:
People know the difference between a nation simply maintaining the nuclear weapons that it currently possesses, and surging forward to cause international trouble. Perhaps we can set minimum expectations for every country on Eaarth, and in any year that they meet those minimum expectations we won’t charge them all sorts of tariffs, boycotts, sanctions. The same applies to individual megacorporations, a few of which deserve to make no profits at all, ever.
A secret side effect of Donald Trump marrying Eastern European women is that he sees the Russians as more human. Kings used to always marry off their kids to foreign kings, in order to keep the international peace.
If Moscow could give the U.S. a square mile of land about 30 miles downwind from the Kremlin, and if Washington could give Russia a square mile of land about 30 miles downwind from the Capitol dome, then both nations could stick representative citizens into these reserves on a rotating basis. Each nation would then have to kill a few thousand of their own citizens in order to get at the enemy. Also, we could meet the enemy in hand-to-hand combat while arm-wrestling at a nearby pub.
Why should only one person get his/her/ze finger on the nuclear button? Give out a dozen nuclear footballs to regular citizens, and then you also need a 2/3 majority (possibly of the surviving football owners) to launch a legitimate nuclear strike. It’s one step for backing down.