Early Sunday morning, Russian warships fired on and captured three Ukrainian Navy vessels in the Azov Sea off the coast of Crimea. The military clash represents a major escalation of the ongoing conflict between Russia and Ukraine, which was triggered by the US and EU-backed far-right coup in February 2014.

According to the official Russian version, three Ukrainian warships illegally entered Russian territory at 7 a.m. on Sunday. Moscow then shut down the strait.

The Russian Federal Investigative Service (FSB), the Russian equivalent of the FBI, confirmed later on Sunday that Russia had seized all three Ukrainian warships. Russia asked for an emergency meeting of the United Nations.

Kiev argues that it had announced the crossing of the strait by the three navy ships but had not received a response from Russia, and that the three ships were attacked by Russian warships in an act of “aggression,” claiming “Russia attacks Ukraine.” The Poroshenko regime also claimed that two Ukrainian sailors had been injured and that one Ukrainian tugboat was hit, and demanded the immediate release of both the ships and all servicemen. It has appealed for support to the EU, the US and NATO.

Ukraine President Petro Poroshenko convened an emergency session of his war cabinet on Sunday. After that, he spoke to the country’s parliament, proposing to introduce martial law for sixty days. Officials of the Ukrainian foreign ministry have since been in frenzied discussions with representatives of the EU and NATO.

Russian media reported that SU-24 fighter jets that are based in Crimea are now flying over the Russian bridge in the Kerch Strait, and that Ukraine had sent naval reinforcement to the area. A military escalation in the Azov Sea had been prepared over months with a series of provocations by the Ukrainian regime which enjoyed the full support of the EU and US imperialism.

In late August, Kiev announced the “transfer of additional forces of the Marine Corps and coastal artillery” to the region.

In late September, Poroshenko officially received two Island-class Coast Guard cutters from the US in Baltimore. On October 12, Poroshenko signed a decree on the Azov Sea which claims that Ukraine had sovereignty over territorial waters in the Kerch Strait and the Azov Sea, and called for measures to counter the Russian navy.

The Poroshenko regime is also looking into pulling out of a 2003 agreement with Russia which provides for the equal division of the Azov Sea between both countries, and a ban on foreign warships entering the sea without the consent of both sides. Ukraine’s pulling out of this agreement would enable NATO warships to enter the Azov Sea.

Last month, the Ukrainian armed forces already held military exercises on the coast of the Sea of Azov, while hosting a major NATO air force drill on its soil called “Operation Clear Sky.” Ukraine’s war drills in the Azov Sea have also contributed to a deterioration of relations with neighboring Hungary in recent months, adding to the explosive tensions in the region.

Poroshenko has made the building of another Ukrainian naval base in the Azov Sea before the end of 2018 a cornerstone of his current campaign for reelection as president in March 2019. The chief of staff of the Ukrainian armed forces, Viktor Muzhenko, recently argued that such a naval base was central to Ukraine’s efforts to fight “Russian aggression.” At this point, Ukraine has two naval bases in the Black Sea region: the West Naval Base in Odessa and the Southern Naval Base in Ochakiv and Mykolaiv.

The new naval base would be located at Berdyansk, close to the territories controlled by the Russian-backed East Ukrainian separatists.

Russia too has increased its military presence in the Azov Sea, and currently has between 50–70 patrol ships there which have started to inspect all vessels going to or from Ukrainian ports. Since the construction of a new Russian bridge over the Kerch Strait was completed earlier this year, virtually all ships transiting into the Sea of Azov from the Black Sea must pass under this crossing.

Poroshenko’s escalation of the military conflict with Russia is driven, to a large measure, by the growing domestic crisis of his regime. Almost five years after an imperialist-orchestrated, fascistic coup brought it to power, the Poroshenko regime is mired in crisis. Recent media reports suggested that some one million people in Ukraine live on the brink of starvation.

Hundreds of thousands have left the country since 2014, fleeing war and social devastation (see: “Ukraine’s depopulation crisis”). The past months saw several strikes by Ukrainian miners, railway workers and other sections of the working class. Polls show Poroshenko with the highest negative ranking of any candidate in the upcoming presidential elections.

In its provocations, the Poroshenko regime has enjoyed the full support of both the EU and US imperialism. Washington has called on Russia to stop “harassing” ships in the past; EU officials have also taken Ukraine’s side in the Azov Sea conflict.

Behind the imperialist support for the reckless provocations of the Ukrainian regime are long-term strategic interests in control over the Black Sea region as a key bridge between Eastern Europe and the energy-rich Middle East and Central Asia. The conflict over the Azov Sea is part of the efforts of US imperialism to curb Russian influence in both Eastern Europe and the Middle East, and encircle the country with US and NATO-backed regimes.

Since the dissolution of the USSR in 1991, all major states bordering the Black Sea, with the exception of Russia, have become either NATO-members (Romania) or went through US-orchestrated “color revolutions” that brought to power thoroughly pro-US regimes (Ukraine and Georgia). Turkey has for a long time already been a NATO member.

For Russia, the Black Sea region has historically been critical for access to the Mediterranean Sea and, in particular, the Eastern Mediterranean where Russia has a naval base of its Black Sea Fleet in Tartus, in the northwest of Syria. The Azov Sea is also central to Russia’s control of Crimea, which continues to be the subject of an economic blockade by the Kiev regime.

An analysis by the US imperialist think tank, the Center for Strategic International Studies (CSIS), noted that for Russia, “Crimea is the military source, Turkey is the pivot, and the Turkish Straits are the strategic throughput; and the end goal is access to and military presence in the Eastern Mediterranean as a counterbalance to U.S. and NATO expansion eastward and its presence in the Aegean and Central Mediterranean.”

Robert D. Kaplan, one of Washington’s most influential foreign policy strategists, emphasized in a recent book that “Europe’s struggle with Russia might not occur only over the Baltics, but over the Black Sea and involve Romania.” He maintained that NATO-member Romania, which also borders the Black Sea, would be the “southern flank” of a war against Russia, while the Baltic States and Poland would form the northern flank.

At the July 2016 NATO summit in Warsaw, NATO leaders pledged to increase their military presence in the region through the creation of the Tailored Forward Presence (TFP). Last year, NATO held a major military exercise in the Black Sea.

Despite all the “Russiagate” clamor of the Democratic Party-led, right-wing opposition to Trump, his administration has actually escalated the military and political support for right-wing, anti-Russian regimes in Eastern Europe, including both Poland and Ukraine. It has supplied the Ukrainian regime with various weapons, missiles and patrol ships, including Javelin missiles—steps that President Obama had still shied away from.

That these US-backed provocations threaten a catastrophic escalation of the military conflict with Russia, which is already well underway through proxy forces in both Ukraine and Syria, is part of the calculation. In an October article for the National Interest, Lyle Goldstein, a research professor at the US Naval War College, openly acknowledged the ongoing provocations by the US-backed Ukrainian regime and warned that a large-scale conflict scenario in the Azov Sea “would make operations in Syria look like a round of croquet.”