Along with his peace efforts, he told The Associated Press that his proudest accomplishments included playing a role in promoting a ban on nuclear weapons tests and extension of curbs on proliferation of weapons technology.
While his efforts with Syria didn't bear fruit, he was more successful in the negotiations that produced a settlement in 1995 for Bosnia, ending a war among Muslims, Serbs and Croats that claimed 260,000 lives and drove another 1.8 million people from their homes.
Some critics said the administration had moved too slowly against the ethnic violence. Then-Congressman Frank McCloskey, an Indiana Democrat, called for Christopher's resignation and virtually accused the administration of ignoring genocide against Bosnian Muslims. A handful of State Department officials resigned in protest.
While Christopher often preferred a behind-the-scenes role, he also made news as deputy secretary of state in the Carter administration, conducting the tedious negotiations that gained the release in 1981 of 52 American hostages in Iran.