By far, the longest war America has fought has been the war on cannabis.
Tens of millions have been imprisoned, hundreds of billions have been spent, marvelous advances have been made, by the anti-pot forces into snooping, and by the pro-pot forces into therapeutic drugs and medical advances.
But the anti-pot forces are no closer to "winning" their war than ever, because pot is not the enemy- their enemy is freedom, and their choice of marijuana as an excuse to attack freedom has paradoxically allied the force of the black market with the seekers of freedom.
Perhaps, in the general gotterdamerung of the end of oil, seekers of freedom will flee America. Alternately, we might realize what a costly and pointless fiasco this all has been. As with so many other things in life, it all gets back to something your mother said- "Don't you have anything better to do with your time?"