So, everybody in the media, including in today's WaPo the usually super-well-informed, David Ignatius, has been declaring that the invasion of northern Iraq by ISIS/ISIL from Syria, and their widely reported opening of the border between the two nations (or "erasure" of it, if you prefer) constitutes "dissolving the Sykes-Picot Agreement of 1916." This makes for an appearance of historical profundity on the part of the commentator, but not if one actually knows the facts.
So, this agreement, initially exposed to public attention by the Bolsheviks in 1917 after they found reports of it (a secret agreement) in the Russian diplomatic files when they seized power in their revolution (and trumpeted accurately as an example of western imperialist machinations in WW I), involved British diplomant, Sykes, and French diplomat, Picot, carving up former Ottoman territories in the Middle East between them. The general account one sees has been that France got what would become Syria and Lebanon (itself carved out for the Christians, who later got outnumbered by Muslims), with the British getting what is now Iraq as well as what are now Israel, Jordan,and the Palestinian territories. (BTW, in the film Lawrence of Arabia, the hero is depicted as knowing nothing of this until late in the film, with the mythical character, "Dryden," played by Claude Rains, explaining it to him; when in reality "Dryden" was Sykes himself who initially hired Lawrence to do his thing and who was fully aware of the agreement from the start).
So, why are all these people wrong? In the original agreement, France was supposed to get what is now the Ottoman province whose capital was Mosul, now officially northern Iraq. But they did not get it? Why not? It was already known that oil was there, and the British already had their troops on the ground there, partly thanks to Lawrence. So, they simply said, "tough luck, it is ours," and later it became Iraq's, with British oil companies getting the contracts on all that oil near Mosul. So, having northern Iraq fall under the control of an entity coming out of formerly French-ruled Syria amounts to finally actually affirming the original agreement as it was set, but not implemented.
Oh, and the character played by Alec Guinness in "Lawrence of Arabia," Prince Faisal, a Hashemite (whose brother, Abdullah, would be made King of Jordan by the Brits, with his great grandson, Adbullah II currently in power), would be set up as King Faisal I of Iraq after Gertrude Bell got Iraq set up with borders and all after WW I, with the support of Lawrence and Winston Churchill. His son, Faisal II, would be killed when he was overthrown by a military coup in 1958 after he hosted and signed the anti-Soviet 1955 Baghdad Pact, on the behest of the US and UK, two years after those two nations overthrew Mossadegh in neighboring Iran and reinstalled the Pahlavi Shah, who also signed that pact.