Istanbul (AFP) - Resentment over the Sykes-Picot Agreement between Britain and France that carved up the Middle East from the ruins of the Ottoman Empire remains, 100 years later, a major factor in Turkish President Recep Tayyip Erdogan's foreign policy.
The May 1916 accord, signed by two British and French diplomats as defeat began to loom in World War I for Germany and its allies, created spheres of influence in the Ottoman-ruled Middle East which to a large extent helped define the borders of modern states including Syria, Lebanon, Iraq and Israel.
After the founding of the Turkish Republic by Mustafa Kemal Ataturk in 1923, the state stepped back from Ottoman imperialism, focusing on building a strong nation within its own borders.
But since Erdogan's Islamic-rooted Justice and Development Party (AKP) came to power in 2002, it has pursued a more ambitious foreign policy, seeking to increase Turkish influence in formerly Ottoman-controlled regions from Bosnia to Saudi Arabia.
Turkey's leadership, accused of neo-Ottomanism by critics, has never hidden its scorn for the Sykes-Picot accord which it says created artificial barriers between Muslim states and deprived Turkey of its natural influence in the region.
"We have always opposed Sykes-Picot because Sykes-Picot divided our region and alienated our cities from each other," Prime Minister Ahmet Davutoglu said in March.
He said the turmoil of the Arab Spring was used to thwart Turkish plans to reverse the outcome of the Sykes-Picot accord, such as by creating a free economic zone with Syria, Lebanon and Jordan.
And now Turkey's enemies are working to create a "new Sykes-Picot" by dividing up Iraq and Syria, he said, as Kurds in particular seek their own autonomous regions.
- 'Narrative of resentment' -
Erdogan has repeatedly railed against Sykes-Picot as the cause of the troubles in the Middle East, saying that "every conflict in the region... had been designed a century ago".
He has also made a particular bete noire of T.E. Lawrence -- the British officer better known as Lawrence of Arabia, who fought alongside Arabs in their uprising against Ottoman rule during World War I -- calling him an "English spy disguised as an Arab".
"Sykes-Picot is influential as a narrative for resentment towards 'Western abuse' and 'reclaiming victory stolen by past injustices', in the rhetoric of the contemporary Turkish leadership," Sezin Oney, political scientist at Bilkent University in Ankara, told AFP.
"Ankara's leadership regards the borders as artificial, limiting or even 'stealing' what belongs to Turkey's historical heritage," Oney added.
With the succession of centenary anniversaries for World War I, Turkish authorities have shown a conspicuous readiness to fete Ottoman victories in a war that the empire did not just lose but led to its disintegration.
In 2015, Turkey staged huge commemorations for the 100th anniversary of the Battle of Gallipoli, where Ottoman forces defeated invading Allied armies.
And this year, Turkey's leaders put huge emphasis on the relatively minor Ottoman victory over a British-Indian force in the 1916 siege of Kut al-Amara (Kut in modern Iraq).
- 'Stinging defeat' -
"One hundred years after Kut al-Amara, we say that its spirit will win out whatever happens and that Sykes-Picot will sustain a stinging defeat," said Davutoglu on the April 29 anniversary.
"With calculations that had nothing to do with reality, they separated the cities, the rivers, the valleys and above all the people" in the region, he said.
Turkey has showed the extent of its post-imperial ambition in the Syria conflict, seeking to oust President Bashar al-Assad to have a major say in the post-war politics of the country. It has also used its military inside Iraq.
Erdogan has eyed reimposing Turkey's grip on parts of territory in northern Syria, floating the idea of a safe zone on the other side of the border that could accommodate some of the 2.7 million Syrian refugees in Turkey, or even a whole new city.
But in many ways the ambition has backfired, with Assad still in power and Turkey itself now the target of Islamist extremists operating from Syria.
"Turkey aimed to step into Syria and Iraq's borders militarily, economically, in recent years with its assertive foreign policy, with quite disastrous results in the case of Syria," said Oney.
It remains to be seen if the shock announcement by Davutoglu -- a former academic seen as the architect of Turkey's foreign policy -- that he is stepping down as premier will change the country's diplomacy.
"Davutoglu's departure brings the prospect of change in foreign policy but I see the chances as quite slim," Turkey's former ambassador to Washington Faruk Logoglu told AFP, adding that Erdogan had rubber-stamped foreign policy designed by Davutoglu.