The partnership between Russia's Vladimir Putin and Turkey's Recep Tayyip Erdoğan has taken the West by surprise. The two leaders met no less than six times in 2019, underscoring the close relationship they've established, one that seems at times built on a mutual interest in riling Turkey's NATO partners.
And this year they already have met twice, with the latest encounter in Berlin at an international conference aimed at resolving the seemingly intractable conflict in Libya, which for centuries was part of the Ottoman Empire, and has been plagued by war and instability since the ouster of autocrat Moammar Gadhafi in 2011.
They've collaborated, too, on Syria, despite backing opposing sides in the long-running conflict and where, as in Libya, they have positioned themselves as twin arbiters. But is this just a marriage of convenience, a partnership that's bound eventually to unravel because of conflicting geopolitical ambitions and the difficulty they face controlling their clients, who are not always pliant?
The Berlin conference this week on Libya, which has turned partly into a proxy war featuring foreign drones, Turkish troops and Russian mercenaries, and its unfolding aftermath, hint at the challenges the two leaders face in reining in their clients. They're trying at the same time to balance their own conflicting regional ambitions to maintain their partnership, according to analysts.
Turkey has been supporting Libya's U.N.-recognized government, led by Fayez Serraj, which has been struggling to withstand a months-long assault on the capital, Tripoli, by rebel commander Khalifa Haftar, who among others is backed by Russia. Both Russia and Turkey have much invested in Libya - Russia in terms of reputation, clout and potential oil deals, and Turkey with even more wide-ranging commercial and energy interests, say analysts.
The Berlin conference, attended by Western powers, too, produced an agreement to respect the U.N. arms embargo, halt outside military interference, and to push Libya's warring parties to observe a cease-fire.
But the complex situation on the ground in Libya has only worsened since the conference - pro-Haftar militias have blockaded two large crude oil production plants in Libya, and on Thursday the Libyan capital's only functioning airport was closed after Haftar's spokesman threatened to shoot down planes flying over the city, dealing another setback to the peace efforts."
Any military or civilian aircraft, regardless of its affiliation, flying over the capital will be destroyed," warned spokesman Ahmad al-Mesmari. He claimed the airport was being used for military purposes by Turkish soldiers sent by Ankara.
Midweek, the airport came under a barrage of rockets. Press reports also suggest that foreign backers have continued to send weapons to Haftar, suggesting no one has the intention of backing down. Either Russia has been unable to rein Haftar in or has not wanted to him to observe the cease-fire, experts say.
Unruly clients also are a problem for Russia in Syria, where Moscow is challenged by growing Iranian influence and is struggling to dissuade President Bashar al-Assad from launching an assault on the remaining major opposition stronghold in the country in the northwestern province of Idlib, according to Russian analysts Kirill Semenov and Dmitriy Frolovskiy.
They note in a commentary for the Middle East Institute, a think tank, that Assad has vowed to "liberate every inch of Syria from foreign troops" and is eager to regain control of Idlib, a move that would endanger the neighboring Turkish enclave in northern Syria and damage Turkish-Russian diplomatic relations. Such a move would upend the efforts by Moscow and Ankara to try to forge a post-war future for Syria that works for both the Turks and Russians, and balances out their interests and influence.
"Putin's recent unexpected visit to Damascus may well have been to personally inform Assad about the necessity of maintaining the cease-fire in Idlib," one which was agreed upon by Moscow and Ankara, they say.
So far, Russia and Turkey have been able to compartmentalize flash-points and disagreements that threaten their partnership and have managed to maintain a rapprochement that started after a Turkish Air Force jet shot down a Russian warplane near the Syria-Turkey border in 2015. Turkey's purchase of a Russian-made S-400 anti-aircraft missile system and cooperation on energy projects is testimony to the partnership.
But some analysts say the relationship is weighted with geopolitical conflicts that risk undermining it. "The Turks have been gravitating to the Russians, even as their vision of Syria directly conflicts with that of Putin," says Jonathan Schanzer of the Foundation for the Defense of Democracies, a Washington-based think tank.
"This could be their greatest divergence. But there are others. They are uneasy about Iran's growing role in the region, which Putin generally backs - so long as it irks the U.S. They hate the Sissi regime in Egypt, which Putin courts. They are at odds with the Israelis, with whom Putin has a solid, working relationship," he says.
Overall, he says the partnership risks collapse because of the grandness of the geopolitical ambitions of the two key players, Putin and Erdoğan, whose long-term aims for their countries are at cross-purposes.
Schanzer points to the grandiose Ottoman vision being outlined by one of Erdoğan's top advisers, retired general Adnan Tanrıverdi, who says Turkey can emerge as an Islamic superpower, wielding authority over 61 Muslim countries with Istanbul as the capital of a new caliphate.
"I see a collision course here," Schanzer says.