Comparing to the DoD budget is just silly. Wiping out the DoD will go about as well as defunding the police.
Better to compare it to something that was a complete waste like the US invasion of Iraq. The unjustified war has been estimated to cost the US over $2B. If we just chose to stay home we would have had half the national debt going into the 2008 recession. Or we could now wipe out all federal student debt and have plenty left over.