Ok, let's do the math.
The US has a GDP of *about* $15 trillion. If we were to end the drug wars ($50 billion) and cut the actual war spending (over $600 billion) in half, and reduce our national health care bill from about 15% of our GDP to about 10% of our GDP by socializing medicine, a la France or Germany, we would have about $1 trillion in hand annually for investment in renewable energy, urban renewal, and electric transit- about 8% of our GDP.
And this is an amount we are already spending annually on stuff of no value. The only downside here is the emotional immaturity of the American people. If we kept spending the money, but on valuable stuff, the people who were making bombs could find jobs making windmills. The products may be rocket science, but the economics aren't.
And even this would not be full employment, or the most good stuff we could produce. Women, people of color, and the elderly are unemployed and under-employed. The potential expansion of our economy if people could just work as much as they want to work is almost unimaginable- to us.
Don't believe me? Do your own research and check it out. And then start trying to think of ways you can be part of the solution instead of part of the problem.