The US doesn't "need" drug money to finance brutal dictators. It's currency is now backed by its military might. It can print as much as it wants and if you even think of trading OIL in another currency they invade and liberate your ass.

While it sounds good, it's pretty bullshit to say the war on drugs is about financing dictators.

It's fair to say that the CIA does have pet opium projects, with US ground troops playing guards for Afghan farmers. But that's a different thing.