That was the secret 1916 treaty by which the British and French carved up the Ottoman Empire, with the Brits taking Transjordan and Iraq, and the French Syria and Lebanon.
Sykes-Picot stuck in the craw of Osama bin Laden. Now his most fanatical followers have given him a posthumous triumph.
President Obama said over the weekend that the Islamic State of Iraq and the Levant, which seeks to create a caliphate out of the Sunni lands of Syria and Iraq it occupies, poses a threat to the United States.
Obama has thus committed 300 special forces to assist Iraq's defeated and demoralized army, and there is talk of U.S. air and missile strikes and drone attacks on ISIS, in Syria as well as in Iraq.
That would constitute a new war. Yet the president, who taught constitutional law, says he does not need Congressional authorization.
He is dead wrong. Not only has he no authority to take America into civil wars in Iraq and Syria, he would be insane to do so without the support of his countrymen, as expressed in a vote by Congress.
Obama is about to make a decision fateful for himself and for his country. Does he not realize that he is on the edge of an abyss, about to stumble into a tribal and religious war across the Middle East?
The Iraq we left behind three years ago no longer exists.
It has been divided up into a Kurdistan, the Sunni region of the north and west, and a Shia-dominated Baghdad and south.
To put the Iraq of Sykes-Picot back together would require thousands of troops to recapture and hold Iraq's border towns and to reimpose Baghdad's rule over Anbar and the Sunni Triangle.
As the Iraqi army has been routed from this region, recapturing these Sunni lands could require U.S. troops in numbers to rival the surge that enabled Gen. David Petraeus to defeat al-Qaida in Iraq.
Yet the situation in the Sunni region is more hostile today.
The Sunni do not want U.S. troops fighting to force them back under Baghdad's rule. Some have welcomed ISIS as allies in the fight to be free of a hated Shia-dominated army and regime.
Some Sunni Arab states are expressing bewilderment that the United States seems about to start a war on the Sunni regions. Are we really going to send planes to bomb and kill our former allies, with their wives and children as collateral damage?