In 2012, Hillary Clinton's State Department, acting through its ambassador, Mari Carmen Aponte, threatened to withhold critical development aid unless El Salvador passed a major privatization law.

Just as much as the United States mattered to cotton, cotton mattered to the United States. Cotton reinvigorated slavery, established the young nation's place in the global economy, and eventually helped create the political and economic conflicts that resulted in civil war.

Toughness' and 'credibility' are leitmotifs that run through both Trumpian and Kissingerian deal-making. Both men insist that war and diplomacy are inseparable and that, to be effective, diplomats need to be able to wield threats and offer incentives in equal, unrestricted measure.

In 2000, just before leaving the White House, Clinton ratcheted up military aid to Colombia. Plan Colombia, as the assistance program was called, provided billions of dollars to what was, and remains, the most repressive government in the hemisphere.