Over the weekend, in the face of what Secretary Kerry called “free-wheeling militia violence,” the United States “temporarily” evacuated its embassy in Libya—not a closure, insisted Kerry, but merely a suspension of activities. But as former U.S. ambassador to Iraq Christopher Hill explained on NPR, “By the time you get to evacuation, you have essentially destroyed all sensitive equipment in the Embassy, you’ve burned everything, every document in the Embassy—[a] very big step.”

Freddie deBoer takes the opportunity to chastise observers who declared Libya a successful intervention: “Libya is in chaos. Nothing was finished. Nothing was successful. The country is broken, utterly broken.” He goes on: “The only pretext for this war was humanitarianism. There was never any self-defense argument made. Since the humanitarian outcome was the only goal, and the humanitarian situation is a disaster, you can’t call Libya a win for intervention.”

A lot seems to be riding on the word “humanitarian” here. Think back to February 2011, when the news was full of chilling dispatches like this:

TOBRUK, Libya — Vowing to track down and kill protesters “house by house,” Col. Muammar el-Qaddafi of Libya tightened his grip on the capital, Tripoli, on Tuesday, but the eastern half of the country was slipping beyond his control.

A bloody crackdown drove protesters from the streets of Tripoli, where residents described a state of terror. After a televised speech by Colonel Qaddafi, thousands of his supporters converged in the city’s central Green Square, wearing green bandannas and brandishing large machetes.

Many loaded into trucks headed for the outlying areas of the city, where they occupied traffic intersections and appeared to be massing for neighborhood-to-neighborhood searches.

“It looks like they have been given a green light to kill these people,” one witness said.

Whatever the conditions of Libya today, Qaddafi did not succeed in killing protesters “house by house.” And that’s not some hazy hypothetical of the kind often found in after-the-fact rationalizations of military intervention. (Well, if we hadn’t intervened, this might have happened…) To the contrary: Qaddafi hadn’t threatened to kill his subjects in huge numbers. He’d vowed to do it. He was marshaling death squads, and untold numbers of Libyans had already been killed (as the Times reported, “one witness said militia forces appeared to be using vans to cart away bodies”). There was not only good reason to believe that his threat was credible; there was already evidence that he was beginning to carry it out.

He did not. That was a humanitarian victory, and a significant one. Now, of course it does not conclusively demonstrate that intervention was a good idea—but no more than the current violence conclusively demonstrates that intervention was a bad one. In essence, supporting the opposition without investing in post-Qaddafi state building amounted to trading one bad outcome (Qaddafi killing civilians) for another (postwar violence and instability).

This raises several questions: Are there good reasons for thinking that our actions led to the lesser of two evils—that Qaddafi’s war against his own people would have been longer, bloodier, or crueler than what Libya is experiencing today? Does the international community—and its so-called guarantors of human rights—have good reason, whether ethical or simply for its own credibility, to intervene when a head of state is promising on television to kill citizens en masse? And can humanitarian interventions be justified only if they produce, as deBoer puts it, “basic material security and democratic power”? Is there a more minimal requirement—of preventing mass killing—that can serve to justify interventions?

I don’t have fantastically convincing answers to any of these questions, and in some cases the best we can do is compare rival expert predictions. But the debate is clouded, I think, by this kind of slippage: “Since the humanitarian outcome was the only goal, and the humanitarian situation is a disaster, you can’t call Libya a win for intervention.” The construction here suggests a consistent meaning for the word “humanitarian”: there was a “humanitarian” goal behind intervening in 2011; there is a disastrous “humanitarian” situation today, and so it follows that the goal of 2011 has failed. But 2011’s goal and 2014’s outcome are not so straightforwardly equivalent. On a minimalist reading, the humanitarian goal in 2011 was to stop Qaddafi from committing mass murder. The fact that preventing a slaughter is not the same as creating an effective government is not, on its own, proof that the humanitarian goal has utterly failed. It’s simply evidence that such goals, while critically important, are also extremely minimalistic. Even successful interventions tend to clear a pretty low bar, and without a protracted investment, it’s unrealistic to expect much more from them than the prevention of outright catastrophe. After the immediate goal has been successfully met, there’s still a huge amount of work to do.