In 1981, he appointed the first woman, Sandra Day O'Connor, a moderately conservative judge from Arizona. In 1986, he promoted conservative Justice William H. Rehnquist to be chief justice and appointed another conservative, Antonin Scalia.

He nominated Robert H. Bork, the conservative who fired special prosecutor Archibald Cox for Richard Nixon during Watergate. But the nomination was defeated after a battle that injected enduring bitterness into confirmation hearings. Reagan had to settle for Anthony M. Kennedy. While hardly a liberal, Kennedy later would vote against overturning Roe vs. Wade, which upholds the right to abortion.

Nor was Iran-Contra the only trouble abroad. In late 1985, four Palestinians hijacked the Italian cruise ship Achille Lauro with 400 passengers aboard. The hijackers surrendered in Egypt, but not before killing Leon Klinghoffer, 69, a New Yorker confined to a wheelchair. He was singled out because he was Jewish.

When an Egyptian plane tried to fly the hijackers home, U.S. Navy fighters forced it to land in Sicily, where they were arrested. The interception gave the administration a boost.

In April 1986, American planes struck Libya in retaliation for a terrorist attack on a West Berlin nightclub that claimed the life of a U.S. serviceman. Libyan officials said leader Moammar Kadafi was not harmed, but three dozen civilians were killed, including his adopted daughter, and that nearly 100 people, including two of his sons, were injured.

The raid was sharply criticized internationally, but it, too, gained Reagan popularity at home.

His overwhelming triumph, however, was an improvement in superpower relations that presaged the end of the Cold War. Nothing displayed Reagan's capacity for political accommodation more clearly than his dealings with Soviet leader Mikhail S. Gorbachev.

During his second term, Reagan carried the burden of his anti-Soviet rhetoric and the stakes he had raised with SDI, his space-based defense program, into four summit meetings with Gorbachev. Reagan doggedly pursued both a reduction in nuclear weapons and better treatment for dissidents and Soviet Jews.

Reagan had three good reasons to reach out to Gorbachev, Cannon says. He had little to show for his first four years in foreign policy. He had built up the military and could bargain from strength. He was freer to deal with the Soviets than any other president because he, of all people, could not be accused of being soft on communism.

Reagan believed in Armageddon. It made him a visionary. "My dream … became a world free of nuclear weapons … ," he said in "An American Life." Because "I knew it would be a long and difficult task to rid the world of nuclear weapons, I had this second dream: the creation of a defense against nuclear missiles, so we could change from a policy of assured destruction to one of assured survival."

But during negotiations, Cannon said, his two dreams clashed. The Soviets refused to retire any of their strategic long-range missiles unless Reagan gave up SDI, his proposed system of defensive missiles to knock down enemy weapons. SDI frightened the Soviets. If it ever worked, they said, it would provide a screen behind which the United States could launch an atomic attack of its own.

Moreover, they said, SDI violated an antiballistic missile treaty in effect since 1972. The treaty permitted laboratory research of antimissile components, but it banned testing and deployment.

On this, too, the Reagan administration was divided. Defense Secretary Weinberger and Assistant Defense Secretary Richard Perle wanted a broader interpretation of the treaty to permit testing. Secretary of State Shultz and Paul Nitze, his leading arms negotiator, said anything but the traditional interpretation would anger the Soviets and cause problems with allies and members of Congress.

As usual, Cannon says, Reagan tried to avoid the disagreement. He said he would interpret the ABM treaty broadly to permit testing, but as a matter of policy he would abide by the traditional interpretation and stop short of conducting any tests.

"A deliberate deceit," the Soviets responded.

So it was that prospects seemed dim when Reagan and Gorbachev sat down on Nov. 19, 1985, in Geneva for their first summit. Reagan was the first U.S. president since Eisenhower to go more than four years without meeting his Soviet counterpart. During those four years, there were three Soviet leaders. They "kept dying on me," he quipped.

From the start, Reagan was relaxed and cordial. As Gorbachev, bundled against the cold, approached the mansion on Lake Geneva where they would hold their initial session, Reagan took off his overcoat and strode out onto the top step to greet him.

In "An American Life," he wrote: "As we shook hands for the first time, I had to admit — as Margaret Thatcher and [Canadian] Prime Minister Brian Mulroney predicted I would — that there was something likable about Gorbachev."

Reagan developed a personal sense of Gorbachev as someone he could deal with. But by afternoon the two of them were arguing about SDI. Reagan said the United States would never launch an initial strike with nuclear weapons and would prove it by sharing SDI technology with the Soviets.

Gorbachev did not believe him. For his part, the Soviet leader said that his nation had no aggressive intentions.