Ludwig von Rochau, a 19th century political scholar, succinctly captured the policies pursued by all governments since time immemorial. The same forces that shape the evolution of animal species also control human societies, he wrote in his influential treatise. In politics, as elsewhere, the law of realpolitik is survival of the fittest. Case in point from a more recent event in American history: Manuel Oriega, a Panamanian warlord supported by Washington for his fight against the Communists, until he no longer became welcomed and the U.S. invaded to take him out.

On this day, December 20, in 1989, to force Manuel Noriega, the leader of Panama and a former ally, out of power, a contingent of U.S. marines and soldiers landed in Panama.

President George H.W. Bush ordered Operation Just Cause citing human rights issues and the protection of American lives and property in the country. He also cited Noriega’s extensive involvement in drug trafficking, which had an especially ironic tinge, given that those same drug deals were ignored by the DEA while Noriega was in good graces with the CIA.