Reagan was elected at a time when yet another generation of twenty-somethings became the dominant generation, another generation harkening for a newfound glory in a world dominated by the Soviet Union. Reagan was an admirer of Richard Nixon, but committed to avoiding the former's mistakes in the Cuban War.
In the 1980 elections, Reagan defeated the pro-reconcilatory Jimmy Carter by winning over the new generation and warhawks from the old, not unlike Nixon. Reagan promised "A new glory to the American nation," not unlike the promises of Nixon.
In 1980, Reagan had his chance: the Soviet Union under Vyacheslav Molotov had begun militarily intervening to help the Sandanistas in Nicaragua in an attempt to overthrow Nicaraguan president Anastasio Somoza. Seeing the intervention as a violation of the Monroe Doctrine, Reagan authorized an invasion of Nicaragua to prevent "The transformation of a nearby ally into a Soviet landing base."
American forces poured into Nicaragua to reinforce Somoza. These forces were armed specifically with anti-guerrilla weaponry, with most tanks armed with flamethrowers in addition to standard cannons. By 1981, American and Soviet forces had each controlled a portion of the country, with the spheres of influence meeting at a line roughly from Puerto Sandino to La Cruz de Rio Grande.
In 1982, the United States began advancing across the line into Soviet territory, beginning the War proper. Soviet and Sandanista forces at first were culled, but then gained the advantage over the American force. Reagan then instituted a draft, the first since the Cuban War.
With several thousand new recruits, the American army was briefly bolstered. However, the Soviets and the Sandanistas had the upper hand by late 1983, passing Patagalpa in October. In desperation, Reagan sent even more troops into Nicaragua, but it was too late. In early 1984, the American force surrendered, and forced to sign the Managua Peace Accords.
With his crushing loss, Reagan was voted out of office in 1984, replaced by Walter Mondale.