The agreement that ended the military campaign against Yugoslavia highlights the critical role played by the United Nations in resolving international disputes. NATO made war against Belgrade; the U.N. made the peace. Hopefully, the U.S. Congress will recognize that simple truth this week, as the Senate debates a bill to pay its debt to the world body. To succeed in its mission, the U.N. needs the United States firmly behind it. As the Kosovo accord makes clear, the U.S. needs the U.N. to accomplish its diplomatic objectives.

The U.S. owes the U.N. more than $1.5 billion. The Senate is considering legislation that would pay $926 million toward that debt. A vote is expected later this week. The Senate is likely to pass the bill, but it faces opposition in the House of Representatives, where antiabortion advocates want to make sure that U.S. funds do not go to family-planning programs that allow abortion. Supporters of the U.N. may be surprised to discover that U.S. foreign policy could be held hostage to what is, essentially, a domestic issue. They should not be: This issue blocked efforts to pay the arrears last year.

Congressional approval is not the end of the process. Payment depends on reform: The U.S. portion of the total U.N. budget must drop from 25 percent to 20 percent, and its share of the peacekeeping bill must fall from 31 percent to 25 percent. Negotiating those changes will not be easy. Fortunately, it looks as if the Senate will confirm Mr. Richard Holbrooke as ambassador to the U.N., a post that has been empty for over a year. The vacancy says much about Washington's priorities.