Thirteen years ago, the U.N. secretary general personally issued a report to the General Assembly on the international community’s failure to prevent the massacre of Bosnians at Srebrenica, which he called “a horror without parallel in the history of Europe since the Second World War.” The searing report criticized member states’ lack of political will and the conduct of the U.N. secretariat. It was all the more remarkable because the secretary general had been the U.N. official in charge of peacekeeping operations then as well as during the genocidal massacres in Rwanda the year before.

That man was Kofi Annan.

Five years after Srebrenica, Annan declared, “The tragedy of Srebrenica will forever haunt the history of the United Nations.”

Speaking in Rwanda on the fifth anniversary of that genocide, Annan lamented that “in their greatest hour of need, the world failed the people of Rwanda. . . . At that time of evil . . . [t]he international community and the United Nations could not muster the political will to confront it.” Five years later he admitted that “there was more that I could and should have done to sound the alarm and rally support.”

There is no reason to doubt Annan’s sincerity. And his willingness to be so critical of the U.N. performance, and his own, in Srebrenica is praiseworthy. Yet the former secretary general is once again at the center of a failure by the international community in the face of a brutal slaughter of defenseless victims. Will he be obliged in a few years to repent yet another failure, this time in Syria?

The best case to be made for Annan is that he is attempting a deal with the devil — in the form of Russia’s Vladimir Putin — to force Syria’s brutal dictator, Bashar al-Assad, from power. But Russia has shown no seriousness about forcing out Assad. While Secretary of State Hillary Clinton said that the recent agreement in Geneva gave Annan “the tools that he needs,” her Russian counterpart told reporters that nothing in that agreement required Assad’s departure.

The cardinal lesson of Srebrenica,” Annan reported in 1999, “is that a deliberate and systematic attempt to terrorize, expel or murder an entire people must be met decisively with all necessary means, and with the political will to carry the policy through to its logical conclusion.” The failure of will was the fault of U.N. member nations. But the U.N. Secretariat and its mission in the field helped delay serious action by pursuing the illusion of “a negotiated settlement with an unscrupulous and murderous regime.” Annan concluded that “At various points during the war, those negotiations amounted to appeasement.”

Writing on this page last week, Annan urged all parties to avoid “further militarization of the conflict” in Syria. That ignores a central lesson from Annan’s own Srebrenica report, that the international community should have confronted the perpetrators of violence with an effective threat of force. Today, we are seeing some of the same weaknesses identified in that report: the “pervasive ambivalence within the United Nations regarding the role of force in the pursuit of peace”; an “institutional ideology of impartiality even when confronted with attempted genocide”; and an effort to “keep the peace . . . when there was no peace to keep.” Negotiations — however well-intentioned — are again providing an excuse for inaction and buying time for the Assad regime to continue the killing.

The Post’s Jim Hoagland reported on this page last month that a European diplomat told him: “Kofi will not go on forever providing cover for others. . . . His resignation would allow the world to see very clearly what Russia is doing — and what the United States is not doing — that makes them both complicit in the killing of a nation. But he also knows resignation is a gun with only one bullet.”

Annan should fire that bullet and stop providing the United States and other self-described “friends of Syria” with excuses for inaction. But whether or not he does, the United States and others cannot blame their failure on Annan. It is long past time to confront the real policy choices.

No one is arguing for military intervention on the order of Afghanistan or Iraq. But the Obama administration should explain why Washington should not be playing an overt, forceful role in organizing and arming the Syrian opposition and exploring with Turkey a coalition of countries to create sanctuaries along the Syrian border, where the opposition could regroup and organize. It should also consider under what circumstances an intervention like the one in Libya might be possible, desirable or both.

If the Obama administration believes that staying largely aloof and leaving others to provide the force behind the Syrian opposition is less risky than a more forceful engagement, let it make that case. But the administration should stop hiding behind the pretense that a negotiation with the butchers of Damascus can do anything but prolong Syria’s agony. The longer that goes on, the worse the aftermath will be. Syria will be more badly broken, with more bloody scores to settle and more power in the hands of the extremists whose specter is too often invoked to justify inaction.

Mark Palmer, a member of the board of Freedom House, is a former U.S. ambassador to Hungary. Paul Wolfowitz, a visiting scholar at the American Enterprise Institute, is a former U.S. deputy secretary of defense and former ambassador to Indonesia.