A century after Britain and France secretly mapped out a Middle East they would control upon defeating the Ottomans in World War One, its borders have been blurred by sectarian bloodshed - and some in the region see opportunity in the chaos.
These include Israelis or Kurds who seek to carve out their own turf, and Arab nationalists or Islamists nursing rancour at Western imperialism. Though diffuse in terms of their clout and aims, they pose a headache for today's global crisis managers.
Nowhere is this more felt than over Syria and Iraq, whose territories diplomats Mark Sykes of Britain and Francois Georges-Picot of France broadly demarcated with pen strokes in the May 16, 1916 pact, and which are now riven by the advances of Islamic State insurgents and Sunni-Shia infighting.
The Sykes-Picot centennial has occasioned conferences and policy papers in Israel. Its premier, Benjamin Netanyahu, argues that Israel's annexation of the Syrian Golan Heights, which it captured in the 1967 war, should be recognised internationally - in part, because Damascus may no longer wield enough central authority to negotiate for a return of the strategic plateau.
Ceding the Golan would put Israel's interior within range of Islamic State weapons, said senior Israeli diplomat Dore Gold.
"The meltdown of borders with the 'Arab Spring' and 'Islamic Winter' has created a reality that points out a number of precautions that Israel has to have in the future," Gold told Reuters in an interview. "Irredentist movements are emerging which challenge boundaries established a long time ago."
Gold said Israel's diplomatic campaign was prompted by the U.N. Syria peace envoy's inclusion in March of the Golan in proposals to reunite a country fragmented by five years of civil war.
Russia, the big power most invested in backing Syrian President Bashar al-Assad against rebel and militant groups, agrees, with its officials saying the Israeli-occupied Golan should remain part of Syria.
"This raises, in my view, the image of some secret meeting in the basement of one of the chancelleries of Europe, where a 21st century Sykes and Picot are sitting with maps and cartographers and trying to reconfigure the borders of the Middle East," Gold said. "You have to put down your flag."
Gold was being hyperbolic - there is no suggestion such meetings are going on - but Israel's need to stake a claim remains.
Kurds Eye Independence
The Kurds, a stateless people numbering in the tens of millions, have seized on disarray to expand oil-rich areas under the autonomous rule in northern Iraq that they have enjoyed since the fall of Saddam Hussein in 2003.
In northern Syria, Kurds controlling three provinces aim to finalize plans later this year for an autonomous political federation
Mindful of U.S. calls to keep Iraq and Syria intact, the Kurds have avoided declaring independence.
But some Kurdish authorities are sounding more assertive.
Under the hashtag "SykesPicot," Masrour Barzani, chancellor of Iraq's Kurdistan Region Security Council, tweeted: "One hundred years of failure & bloodshed is enough reason to try a new path. For #Kurdistan it's time to undo the injustice."
"Some say now isn't the right time for an independent Kurdistan. I believe it's time for our people to finally determine their own future," he wrote.
These are unwelcome sentiments in Baghdad or other Arab capitals struggling to contain regional ruptures.
But there is popular support among many Arabs for deeming Sykes-Picot dead. Secular nationalists want to solemnise the end of often arbitrary Western-imposed boundaries. Islamists hope to unite co-religionists in a Muslim caliphate.
"Sykes-Picot partitioned the Arab world and prepared the ground to absorb the Zionist entity and execute the plot to set it up and to keep Arabs weak," said Jamil Abu Bakr, a leading member of Jordan's Muslim Brotherhood, in reference to the 1948 creation of Israel in what had been British-ruled Palestine.
Palestinians worry the pan-Arab sectarian furies may detract from their goal of statehood in Israeli-occupied territory.
Hanan Ashrawi, a senior member of the Palestine Liberation Organisation, lamented the "perfidy and betrayal" of colonial deals like Sykes-Picot, but said the resulting Arab nation-states should be preserved lest partition bring more suffering.
Referring to the Golan, she said Israel was "exploiting the situation in order to attempt to consecrate, to make an illegal occupation of Arab land permanent - including in the West Bank".