AFTER a military coup brought Juan Velasco Alvarado to power in Peru 21 months ago, United States relations with that country almost degenerated into a cold war. Angered by what Peruvians called the "unjust enrichment" of the International Petroleum Co., Velasco seized the company's oilfields. Subsequently, Peru also took over U.S.-owned sugar lands. Only intervention by Richard Nixon stayed U.S. retaliation under the Hickenlooper Amendment, which would have imposed economic sanctions on Peru. Even so, the diplomatic climate was markedly frigid, and Peru went unabashedly seeking Russia's aid to play against its traditional ally.
Then last May catastrophe struck. One of the...