But in the past five years, frustration has mounted. Gruesome drug crimes have brought record levels of violence to swaths of Mexico and Central America, despite the billions that the US has poured into the antinarcotics fight.
Leaders in the region are pleading for new alternatives – some are even discussing legalized drug markets – no matter how much those ideas might alienate the US.
IN PICTURES: The Latin American Drug War
The restiveness reflects a growing political assertiveness in the region. While Latin America has always been weary of the heavy hand of the US, Bolivia and Venezuela have taken their indignation to a new level, refusing to cooperate with the DEA and other US officials. Many countries also seem less inclined to genuflect toward Washington on other issues, from trade to foreign policy.
Yet it is the drug issue that will most define US relations with the hemisphere – and have the most impact around the world. Latin America remains the world's No. 1 supplier of cocaine, and how various countries deal with their coca tracts will not only affect the flow of narcotics, but might lead to new strategies in the drug fight.
For now, the range of ideas and possible routes of action vary widely. Leaders in the most vociferous countries even concede that their ideas might not work. But what seems certain is that the days of policy dictated so heavily from Washington are vanishing.