The US federal government will not end the drug war on its own, but may do so to avoid the appearance of complete obsolescence. Cities, counties, and states will continue to nullify federal regulations and drug schedules until the drug war has ended de facto. Once ended in the US, the domino effect will make its rounds globally. Few countries will maintain strict drug laws after.
The true history of the drug war is now accessible to the public. Though the war on drugs has roots back in the early 1900's starting with Henry J. Anslinger, Nixon's administration created the global war on drugs. We have found that Nixon unsurprisingly lied about his motives in criminalizing drugs. As usual the beneficiaries of this legislation were never to be the American people, but the politicians own agenda.
According to John Ehrlichman, one of Nixon's top aides, the true intent of the war on drugs was to disrupt their political enemie's communities. The left and the black community. The anti-war people. Nevertheless, Nixon was later impeached for a different scandal.
Different administrations found the war on drugs useful to their agendas in different ways. Ultimately, it has been the lobbies of the pharmaceutical, alcohol, tobacco, and others that has prevented any sort of real reform on a national level. This collusion between the federal government and big corporations is now very obvious to a majority of Americans. Recent polls show that a majority of Americans are in favor of Marijuana legalization.
So as it usually happens, the crony interests are enforced against the will of the people until they simply cannot be. Eventually the federal government will fear having the image of complete obsolescence and tyranny and so will be forced to end the war on drugs at some level, either by granting these powers to the states themselves, or some other means. This has recently occurred for medical marijuana users.
I suspect that we are now witnessing the beginning of the end of the war on drugs. As well, an economic crash in the near future may increase demand for illicit substances which would function as a catalyst for reform. Our overlords wouldn't risk the image of not caring for the sick, the poor, and the less fortunate in desperate times.