It stands to reason that anyone who wants to topple the Assad regime in Syria would have an incentive to implicate the regime in the use of chemical weapons. Establishing a casus belli for American, Israeli, or European intervention may require such a stunt.

The United Nations independent commission of inquiry on Syria has not yet seen evidence of government forces having used chemical weapons, which are banned under international law, said commission member Carla Del Ponte.

“Our investigators have been in neighboring countries interviewing victims, doctors and field hospitals and, according to their report of last week which I have seen, there are strong, concrete suspicions but not yet incontrovertible proof of the use of sarin gas, from the way the victims were treated,” Del Ponte said in an interview with Swiss-Italian television.

“This was use on the part of the opposition, the rebels, not by the government authorities,” she added, speaking in Italian.

Where did the rebels get their sarin gas? That is anybody’s guess.

But once sarin gas was used it wasn’t long before the usual suspects began clamoring for war. When Obama stated that the use of chemical weapons would cross a red line, he was trying to deter the Assad regime from using them, but he invited a false flag operation that would make him look weak or hypocritical if he didn’t act on it. As recently as yesterday, David Sanger was nailing the administration for fecklessness in the pages of the New York Times.

In fact that debate has begun to shift in favor of more action, administration officials say. Mr. Obama’s legalistic parsing of whether his “red line” for intervention was crossed when evidence arose of a limited use of sarin gas has prompted many of his allies — led by Israeli officials — to question the credibility of his warnings.

One administration official acknowledged late last week that the critique had “begun to sting,” but said that Mr. Obama was determined to go slowly, awaiting a definitive intelligence report on who was responsible for the presence of sarin before deciding on a next step.

Maybe the president should get credit for smelling a rat. People have been pushing him to war with increasing fervor.

So far among the most reluctant members of the administration to intervene heavily in Syria has been Mr. Obama himself. He declined to arm the rebels last fall, despite urging from Secretary of State Hillary Rodham Clinton and the C.I.A. director at the time, David H. Petraeus.

On Sunday, Senator Patrick J. Leahy, Democrat of Vermont, said he believed the administration was getting closer to a decision. “The idea of getting weapons in — if we know the right people to get them, my guess is we will give them to them,” Mr. Leahy said on “Meet the Press.” Last week, Defense Secretary Chuck Hagel said that arming the rebels was under consideration.

Now that it appears that the rebels committed war crimes and used sarin gas, do any of these war hawks conclude that international action should be taken against them? Do any of them consider how they were tricked? No and no.

These people serve the dark masters of war. They are not bound by humanitarian concerns or laws or the quest for the truth. They would have us fight a war to avoid the very appearance of weakness, irrespective of how weak we would look once we were bogged down in a regional proxy war between Sunnis and Shiites, Israelis and Hizbollah, and Saudis and Iranians. They would leap to commit our troops at the mere rumor of chemical weapons use by the Assad regime, but will simply ignore their use by the rebels.

Even relatively peace-minded people like Sen. Patrick Leahy think we can find “the right people” to deliver arms to. But the small sliver of pro-Americans on the rebel side will never be big enough to control the outcome or the aftermath of this war. And that’s being generous, because I don’t think there are any pro-American forces.

Meanwhile, Israel is blasting away at Syria. Shells suddenly land in the Golan Heights. The regional players know only how to inflame the situation, not how to cool it down.

Syria has been a repressive dictatorship for decades, but it was an ecumenical society where people of different ethnicities and religious beliefs got along quite harmoniously. It does not appear that that condition can be restored to Syria, and it is a great shame. But we should be under no illusions that any of the possible winners of this civil war will be positively disposed towards the United States or to Israel. In that regard, it won’t make a bit of difference if Saudi-backed Sunnis win or Iranian-backed Shiites and Alawites win. And the winners will instigate a program of ethnic-cleansing, wherein Arabs are separated from Kurds, Alawites are separated from Sunnis, and Christians run for cover. If the Assad regime falls to Saudi-backed Sunnis, the war will continue as Shiites in Iraq, Iran, and Lebanon back an ongoing rebellion against the new regime. Do we want to be a party to genocide? Where does our tiny phalanx of “the right people” fit into this nightmare?

We would all like to put Humpty Dumpty back together again and restore to Syria its previous harmonious conditions with a coalition government willing to have representation from all factions. But, just as it has turned out to be in Iraq, this is a pipe dream. The international community should certainly try, but military intervention by the United States isn’t going to perform a miracle.

The only person in a position of responsibility who seems to have his or her head screwed on right is the president, but he is under a lot of pressure to succumb to the forces of darkness.