A gradual move toward democracy or a non nuclear dictatorship would seem to be the preferred options.
That's a good idea for a future version of the US.
We're a long way from such a Utopia. And even further from a transference of such a Utopia to an imposition of such a model on subjugated states such as Vietnam, Syria, Iraq, Korea, et al.
First, remove nuclear weapons from the imperial countries; then invite truly free countries to follow suit.
Then there may be peace.