As the Kosovars’ suffering adds a somber note to the celebration of NATO’s 50th anniversary this week, so NATO’s military intervention in Yugoslavia highlights a discomfiting chasm that has developed not simply between NATO and the United Nations, but also between the ideal of justice and the rule of law.

So far, NATO members have attempted to talk around and over that split. But the legitimacy of the Yugoslav intervention, which has proceeded without the authorization of the U.N. Security Council, and that of all future interventions cannot rest on well-meant obfuscation. NATO must urge the rethinking of international understandings so that both law and justice can be served.