Warren M. Christopher, who helped negotiate a settlement to the Iran hostage crisis in 1980 and who confronted the ethnic violence in the Balkans and Rwanda while serving as secretary of state during President Bill Clinton’s first term, died March 18 at his home in Los Angeles of complications from kidney and bladder cancer. He was 85.

When Mr. Christopher became the 63rd U.S. secretary of state in 1993, he was already known to the public as an effective, if circumspect, negotiator who played a crucial role in brokering the release of the U.S. hostages in Tehran on the day Jimmy Carter yielded the presidency to Ronald Reagan in 1981.

Earlier he had been the Carter administration’s point man in persuading the Senate to ratify the Panama Canal treaties, which eventually ceded U.S. control of the canal to Panama. He gained the support of crucial senators as the architect of a “reservation” giving the United States the right to protect the canal and then managed to persuade the Panamanians to accept the provision.

When he was named Clinton’s secretary of state, Mr. Christopher was considered the veteran hand who would complement the former Arkansas governor’s limited foreign policy experience.

Mr. Christopher’s primary responsibility was to ensure that crises in foreign policy did not undermine or interfere with the president’s domestic agenda. It was the first time in more than a half-century, Clinton would later say, that the United States was “without a single, overriding threat to our security.”

As a diplomat, Mr. Christopher projected an image of discretion and unflappability. People magazine included him in a feature on the best-dressed men in America. Dressing well, he said, “is a mark of the respect you have for others.” His language was reasoned but often noncommittal. His stock answer to questions about his personal success was “I've been very lucky.”

Writers and commentators characterized him as dour, attentive to detail, patient, steady and poised, but rarely, if ever, charismatic. Clinton once joked that Mr. Christopher was “the only man ever to eat presidential M&Ms with a knife and fork.” No one was surprised when, on an official stopover in Ireland, he ordered Irish coffee, decaffeinated and without alcohol.

In a normally high-profile office, Mr. Christopher shunned publicity, and he disliked being in the spotlight. It was on his watch as secretary that peace accords were reached in 1995 in Dayton, Ohio, ending a three-year war and ethnic slaughter in Bosnia, but much of the news media attention was focused on Assistant Secretary of State Richard C. Holbrooke, who had handled the nitty-gritty of the negotiating. Mr. Christopher later described the agreement as “one of the greatest achievements in American diplomatic history.”

Almost four years after stepping down as secretary of state, Mr. Christopher, a senior adviser to Al Gore’s 2000 presidential campaign, returned to the public arena as chief of the team that litigated the results of the Florida recount.

But the lion’s share of public attention went to lawyer David Boies, who did most of the courtroom work. Ultimately, the U.S. Supreme Court ruled in favor of Republican George W. Bush, whose legal team was spearheaded by another former secretary of state, James A. Baker III.

At State, a tumultuous start

As secretary of state, Mr. Christopher told U.S. News & World Report that his “first priority” was to “attack problems before they reach the crisis level” and to keep the United States from expending lives and fortune in international disputes.

“I’d much rather be known as somebody who was a preventer of crises than as a crisis manager,” he said.

But he had a tumultuous beginning. In May 1993, just months into his new job, Mr. Christopher went to Europe to solicit Allied support for a plan to end ethnic cleansing in the Balkans by arming Bosnian Muslim forces and launching airstrikes against Serbian targets. He was unsuccessful and returned to tell Congress that Bosnia had become “a problem from hell.”

Eventually, NATO would agree to a bombing campaign against the Serbs, which Mr. Christopher described as critical in ending the Bosnian slaughter.

In Somalia, what began as a humanitarian relief effort in the final days of the George H.W. Bush administration ended with the withdrawal of U.S. forces in March 1994 in the aftermath of the deaths of 18 U.S. soldiers in Mogadishu.

A month later, the Clinton administration became aware of a systematic slaughter in the African state of Rwanda that left an estimated 800,000 dead, most of them Tutsis. But the United States and other Western nations opted against intervention, and Mr. Christopher authorized State Department personnel to use the word “genocide” only under limited conditions.

Critics later contended that avoidance of the genocide characterization made it easier for the United States to follow a hands-off policy. In 1998, on a visit to the Rwandan capital of Kigali, Clinton said the United States had not acted quickly enough and apologized for not calling the killings genocide.

Mr. Christopher also had little success on a 1994 diplomatic trip to China, which was marked by a roundup of dissidents despite Mr. Christopher’s advocacy on behalf of human rights.

In spite of these setbacks, Mr. Christopher had several important international accomplishments as secretary of state. He accompanied the popularly elected Jean-Bertrand Aristide back to Haiti in 1994 following his restoration to power after an intervention by U.S. troops, acting under a U.N. mandate.

He played an important role in the signing of peace accords between Israel and the Palestine Liberation Organization and sought to resolve conflicts between Israel and Lebanese militants. But, like other special envoys, he failed to bring lasting peace to the Middle East.

He did the preliminary diplomatic groundwork for the expansion of NATO and extended a nuclear non-proliferation treaty with North Korea.

After the Republican victories in the 1994 midterm elections, Mr. Christopher was reportedly ready to resign.

According to a 1996 report in the New Republic, he offered his resignation, but it was rejected by Clinton after Gen. Colin L. Powell and Sen. Sam Nunn (D-Ga.) declined the post.

Mr. Christopher stepped down as secretary of state in early 1997, tendering his resignation after Clinton’s reelection, and was succeeded by U.N. Ambassador Madeleine K. Albright.

In his book “War in a Time of Peace,” David Halberstam wrote that some senior Democrats considered Mr. Christopher “too much the functionary, a capable and highly competent bureaucrat, but probably a limited one, a man lacking originality and beliefs of his own.”

He was said to have surrendered initiative on foreign policy to others, including national security adviser Anthony Lake and the deputy secretary of state, Strobe Talbott.

But there was a toughness about him too. Washington Post columnist Jim Hoagland once quoted a top Democratic Party operative as saying that Mr. Christopher was “the person you want to give an air of dignity to a knee to the groin if it has to be thrown.”

In Tokyo Bay

Warren Minor Christopher was born Oct. 27, 1925, in Scranton, N.D., the fourth of five children. His father, Ernest, managed a local bank and was forced to foreclose on friends’ and neighbors’ homes during the Depression.

After suffering a stroke at 49, Ernest Christopher moved his family to Hollywood for the healthful climate. But when he died not long afterward, the younger Mr. Christopher was forced to support the family. He never forgot being thrust into poverty.

He graduated from the University of Southern California while serving in the Navy during World War II. His ship was in Tokyo Bay when the Japanese signed the documents of surrender on Sept. 2, 1945. Before returning to the United States, he had a chance to go ashore for an eyewitness view of the war’s devastation.

“What I saw on that trip has stayed with me,” he wrote in his 2001 memoir, “Chances of a Lifetime.” “Large groups of frightened Japanese huddled together in the streets, drifting aimlessly, hungry and homeless.

“When someone mentions war, these are the images that are called up for me. Not flags waving or bands playing, but rubble, hardship and suffering.”

After the war, Mr. Christopher went to Stanford Law School, where he was a founder and the first president of the Stanford Law Review. He spoke of being awakened to the study of international affairs by the new law school dean, Carl Spaeth, who had been a Latin American specialist at the State Department during World War II.

Spaeth helped his young protege gain a yearlong clerkship under U.S. Supreme Court Justice William O. Douglas after Mr. Christopher graduated from Stanford in 1949. He then returned to California and joined O’Melveny & Myers, a blue-chip law firm where he would remain for the private-sector phase of his career.

Enters government work

In 1958, Mr. Christopher was a speechwriter for the successful California gubernatorial election campaign of Democrat Edmund G. “Pat” Brown. Mr. Christopher reportedly crafted the phrase “responsible liberalism” to describe Brown’s approach to social issues. In 1965, Brown named Mr. Christopher vice chairman of the governor's commission on the riots in the Watts section of Los Angeles.

Mr. Christopher drafted the commission’s report, which amounted to a plea for better housing, education and jobs. In 1991, Mr. Christopher served on the commission that investigated the Los Angeles riots after the police beating of Rodney King. That commission’s report, which detailed police misconduct and racism, proposed significant reforms that were overwhelmingly approved in a referendum.

In 1967, Mr. Christopher came to Washington as deputy attorney general to Ramsey Clark in the Johnson administration. That summer, he recommended sending the Army's 82nd Airborne Division to Detroit to quell rioting.

During the unrest that followed the assassination of the Rev. Martin Luther King Jr. in 1968, he coordinated efforts to control disturbances in Chicago.

He returned to his Los Angeles law practice during the Republican presidencies of Richard M. Nixon and Gerald R. Ford.

In 1977, Carter selected Mr. Christopher to serve as deputy secretary of state under Cyrus Vance. At his confirmation hearings, Sen. Jacob K. Javits (R-N.Y.) charged that the nominee had known of and condoned illegal Army surveillance of domestic dissidents while he was serving in the Justice Department.

Despite Mr. Christopher’s denials, the allegation resurfaced 20 years later when the Associated Press uncovered a memorandum with Mr. Christopher’s initials indicating that he was aware of the surveillance. His aides said he must have forgotten the matter, and it faded from the public spotlight.

The Tehran crisis

As deputy secretary of state, Mr. Christopher was the Carter administration’s point man in denouncing the 1979 Soviet invasion of Afghanistan and supporting a U.S. boycott of the 1980 Summer Olympics in Moscow. He was also charged with informing Taiwan that the United States would normalize relations with mainland China.

In November 1979, Iranian students seized the U.S. Embassy in Tehran, taking 52 Americans hostage. After a helicopter rescue attempt failed in April 1980, Vance resigned as secretary of state.

Hoping to be named Vance’s successor, Mr. Christopher was disappointed when Carter appointed Sen. Edmund S. Muskie (D-Maine). According to his memoir, he considered resigning, but after a long nighttime jog, he decided against it.

Mr. Christopher immersed himself in the hostage negotiations and often shuttled back and forth to Algeria, whose government was acting as an intermediary. On Jan. 16, 1981, Carter awarded him the Medal of Freedom, the nation's highest civilian award.

In his personal life, Mr. Christopher was a tennis player and jogger, although as he aged he would confess, “I've been demoted to walking.” In December 1956, he married Marie Josephine Wyllis, a former schoolteacher.

She and their children survive, along with a daughter from an earlier marriage.

Rarely did Mr. Christopher display emotion in public. But on Jan. 20, 1981, as Carter was yielding the presidency to Reagan in Washington, Mr. Christopher was in Algiers to greet the planeload of freed hostages on the first leg of their journey home to the United States. It was a moving occasion, even for the usually stoic and reserved Mr. Christopher.

“There were very few people with dry eyes, and I was not among them,” he said.