The attraction of making the US a large, economy size Sweden or Switzerland
is
certainly powerful.
But you must consider that the withdrawal of the US from the world
political/military scene would leave a power vacuum. This would be filled by
another power--and not without

serious disruptions and violence. A comparison
might be to what happened with the demise of Ottoman and Austria-Hungary
power.
It's very likely the US would be drawn back onto the world military stage by

Well this is basicly "the redistrubition of post WWII accumulated wealth" game
but accelerated because of scientific and technological advances.
If you and your potential adversaries have ability today to use HPM weapons as
tectonic and climatic weapons and if you know today that they (HPM) going to
render nuclear weapons useless,then must do something and very fast.
The Martialization of society might be one of the answers to face HPM weapon
threats and natural disasters.