Discovery
In 1986, the entire Iran-Contra scheme came to light after a leak by an Iranian military commander was published by a Lebanese newspaper. Immediately, Congress and the American public were shocked by the far-ranging nature of the conspiracy. and the boldness with which the Reagan Administration had flaunted the Boland Amendment. Congress immediately moved to investigate the entire affair.
Investigation
Three investigations were launched: one by the White House, one by the House of Representatives, and one by the Senate. The committees ran into problems early on.
During these investigations, it was privately revealed that Ronald Reagan had alzheimer's disease, a degenerative brain disease. This meant that the President's mental capacity was reduced, which brought into question how "in control" of events he really was. Additionally, there was concern amongst the investigators that they did not want "another Watergate," in which the President was found to be engaged in obvious criminal activity.
As such, the investigators focused on underlings, most notably Colonel Oliver North, a Marine Corps officer who had overseen the day-to-day operations of Iran-Contra and Secretary of Defense Caspar Weinberger.
Outcomes
In 1990, the Contras agreed to a ceasefire and to hold elections. However, the United States placed Nicaragua under a blockade and said that the only way Nicaragua could begin trading with the rest of the world again would be if Nicaraguans put the Contras in power. The blockade was devastating; the Nicaraguan economy was crippled and shortages of medicine, food, and other essentials were cut off. Despite high popularity, the Sandinistas were voted out of power, in the face of American economic pressure. By the time the entire affair was over more than 30,000 Nicaraguans had been killed and much of the country destroyed.
In 1988, Iran and Iraq agreed to a peace treaty. The borders were restored to where they had been before the fighting started. Nothing had changed on either side, save that more than 1 million people had been killed and both countries had suffered terrible damage.
In the United States, Oliver North and Caspar Weinberger would receive pardons for their crimes by President George H. W. Bush before facing trial. Both men would go on to have lucrative careers in the public sector.
This 4:44 video is of Reagan defending his behavior during the Iran-Contra Affair.
This 6:56 video is a Saturday Night Live clip written about the events of the Iran-Contra Affair.