Russia HUMILIATED AGAIN as Turkish Warships block russian navy, refuses passage through straight.

Erdogan has a trump card against Putin that would transform the Syrian warFollowing the downing of a Russian warplane, Russia has shown no signs of letting up on its military operations near the Turkish-Syrian border.
Prior to the incident, Moscow ignored calls by Ankara to put an
"immediate end" to its airstrikes on Turkmen rebel brigades operating
along the border.
The tension culminated in Turkey's decision to down the Su-24 fighter jet, which had been bombing units of Liwa Jabal al-Turkman — an ethnic Turkish group backed by Turkey — at the time it was downed.

Russia insisted the plane had been bombing "terrorists" in the area.

Burned by the incident, Russia deployed an advanced S-400 surface-to-air missile system to the coastal province of Latakia that all Russian Su-24s be equipped with air-to-air missiles. Russian warplanes pounding Turkmen rebels — the Turkish along the border that supply them — with airstrikes.

These provocative moves are evidently meant to deter Turkish jets from shooting down Russian planes in the future. But Russia has
in keeping its retaliation asymmetrical — specifically, by bombing
Turkish-backed rebel groups in Syria while refraining from engaging with
Turkey in a military confrontation directly.
Osman Orsal/ReutersRussian President Vladimir Putin and Turkish then-Prime Minister Tayyip Erdogan.

Asymmetrical or not, Turkey could feasibly perceive
Russia's military buildup along the Turkish-Syrian border as a serious
threat and invoke its most valuable trump card: the Turkish Straits.
The straits, which consist of the Dardanelles, the Sea of Marmara, and the Bosporus, are a series of waterways in Turkey connecting the Aegean Sea — and the Mediterranean — to the Black Sea.

Turkey, which has full control over the Dardanelles and the Bosporus under the 1936, acts as the straits' custodian and regulates the passage of naval ships belonging to Black Sea states.

Russia currently depends on the unrestricted access to the straits
afforded it under the Montreux Convention. Through the straits, it sends
supplies to Syria from its Novorossiysk naval base in the Black Sea to Russian ports in Tartus and Latakia.
Google Maps

Historically, Russian ships have enjoyed unfettered access to the
Mediterranean via the straits. Under Montreux, however, Turkey may
legally block Russian military vessels from passing through the straits
under two conditions: if it is at war with Russia or if it considers
itself to be "threatened with imminent danger of war."
As Aaron Stein, a Turkey expert and nonresident fellow at the Atlantic Council, told Business Insider on Tuesday, it remains unlikely that Turkey would go as far as to close the straits — even in these tense times.

"I think this scenario would only kick in a World War II type
situation," Stein said in an email. "Turkey will keep the straits open
per the convention and its historical practice."
But against the backdrop of Russia's escalating military presence
along Turkey's southern border is Ankara's legal authority, under
Article 21 of Montreux, to cut off one of Russia's most vital links to
Syria if it feels threatened with war.
Turkey has already reportedly signaled that it is willing to take
some steps of retaliation with the straits. Leonid Bershidsky, a
Bloomberg View columnist, that Turkey is "making Russian cargo ships wait for hours before they're allowed to pass through the Bosporus."
Khalil Ashawi/Reuters

That Russia has continued to target Turkmen villages and rebel
brigades along the Turkish-Syrian border, despite Turkey's demands that
it stop, would theoretically be enough for Turkey to invoke Article 21.
"It was the targeting of these Turkmen groups, villages, and
convoys that led to Turkey summoning the Russian ambassador and
demanding a halt to the strikes," The Soufan Group "Less than a week after, Turkey shot down the Russian jet."
Though Russia wants to weaken the Turkmen rebels so that they do not
return to central Asia and strike Russia — and so they are less capable
of fighting Syrian President Bashar al-Assad's forces — Turkish
President Tayyip Erdogan is equally if not more invested in the continued well-being of the Syrian Turkmen, who are ethnically Turkish.
"Erdogan's determination to create a pan-Turkic sphere of
influence is matched by Russia's to target Syrian Turkmen," the group
added. "It is difficult to overstate how much this issue resonates with
Turkey's and his government."
ReutersMap of Syria locating the Turkmen region and Russia's declared targets in the zone since September 30.

It is also difficult to overstate how important the Turkish straits are to Russia's continued military campaign in Syria.

"The so called Syrian Express deployments of Russian
Ropucha and Alligator class landing ships and auxiliaries are vitally
important to keep Russian troops inside Syria supplied," Cem Devrim
Yaylalı, a Turkish naval analyst, over the weekend.
"If Russia cannot send its ships through the Turkish
Straits for any reason, the Russian soldiers deployed in Syria may find
themselves in a very similar position of General Paulus' Army," he
General Paulus was a Nazi commander in World War II who
led Germany's drive on Stalingrad beginning in 1942. He and his troops
were ultimately forced to surrender after their assistance from
Germany's Sixth Army was cut off by strong Soviet Army formations.
The Germans' defeat at Stalingrad is said to have marked a turning point in the war, leading to the Allies' victory in 1945.

Yaylalı implied that Russia and Russian-backed
troops in Syria could suffer the same fate if Russian naval ships are
blocked from reaching the eastern Mediterranean and can't resupply their
troops. Given how much pro-regime elements have benefited from Russian
weapons and supplies since the war erupted in 2011, it is not an
unreasonable prediction.
Boris Zilberman, a Russia expert with the Foundation for
Defense of Democracies, noted how keeping its access to the straits —
and to Syria — and avoiding a larger-scale conflict with NATO has likely
factored in to Russia's decision to keep its retaliation limited and
"Putin's options are limited," Zilberman said in an email, which is why he is "taking action on the margins/asymmetrically."

"That being said ... the Russian-Turkish relationship is a
tinderbox," he added. "The deterioration in the relationship is a loss
for both Moscow and Ankara. The egos of Putin and Erdogan may spin any
future incident beyond control."