Moscow and Washington traded accusations yesterday over an incident involving US reconnaissance aircraft and Russian SU27 fighters in the Black Sea that once again demonstrates how perilously close a military clash between the two nuclear-armed powers is.

Two US defense officials denounced Russia for carrying out an “unsafe and unprofessional” act by flying within 10 feet of two US spy planes conducting patrols over the Black Sea. A Pentagon spokesman told RT that a P-8A Poseidon aircraft was conducting “routine operations in international airspace” when it was approached by the fighter jets around 11:20 a.m.

The Russian Defense Ministry shot back that two US planes approached the Russian border after turning off their transponders, a radar signal used by others to identify a plane’s location. The jets were acting “in strict accordance with international flight rules,” the statement from Major General Igor Konashenkov continued.

Whatever the precise cause of the incident and regardless of who provoked it, primary responsibility for the exacerbation of tensions in the Black Sea region and throughout Eastern Europe lies with US imperialism and its NATO allies. Since backing a right-wing coup in Kiev in February 2014 to topple Ukraine’s pro-Russian President Viktor Yanukovych, Washington has pursued a deliberate policy of isolating and encircling Russia both economically and militarily.

The presence of the US spy planes in the area was highly provocative given that Russia had just begun a major war games exercise code-named “Caucasus 2016.” Part of President Vladimir Putin’s reactionary stoking of nationalism and militarism in response to the US-led imperialist aggression, the exercise runs from September 5 to 10 and involves 12,500 servicemen, including ground, air and naval forces. The Black Sea fleet based in Crimea and the Caspian Sea flotilla participated.

This mobilization pales in comparison to NATO’s largest military exercise in its history, which was held earlier this summer and involved over 30,000 armed forces personnel in maneuvers aimed explicitly at Russia.

US officials have continued to ratchet up tensions with Moscow. In a blistering attack on Russia in a speech delivered at Oxford University Wednesday, Defense Secretary Ashton Carter cast Moscow as the principal destabilizing force in the world today. “Despite the progress that we made together in the aftermath of the Cold War, Russia’s actions in recent years—with its violations of Ukrainian and Georgian territorial integrity, its unprofessional behavior in the air, in space, and in cyberspace, as well as its nuclear sabre rattling—all have demonstrated that Russia has clear ambition to erode the principled international order,” he declared.

Such brazen lies, which are repeated incessantly by a compliant media, turn reality on its head. Since the dissolution of the Soviet Union by the Stalinist bureaucracy in 1991, Washington has been the chief cause of global instability as it has sought via military means to offset its protracted economic decline and retain its unchallenged position as the global hegemon.

Successive US governments have systematically worked to expand their sphere of influence at Russia’s expense, above all by shifting NATO’s borders more than 800 miles to the east through the incorporation of former Warsaw Pact states, and even former Soviet republics, into the US-led alliance.

In the wake of the Kiev coup, Washington heightened the stakes still further when President Obama proclaimed that the US had an eternal commitment to defend the Baltic republics against “Russian aggression”–a commitment he reiterated earlier this year. The US has thus vowed to go to war in support of virulently anti-Russian regimes and has positioned military forces little more than five minutes flying time from St. Petersburg.

Carter also made an oblique reference to unsubstantiated allegations that Russia was behind the hacking of emails from the Democratic National Committee (DNC) when he warned ominously that the US would respond to attacks on “our democratic structures.” These allegations have been used by the Democratic presidential candidate Hillary Clinton and the media to attack Republican Donald Trump from the right for being too close to Russia and prepare the ground for a massive escalation of military violence after the election.

Washington and its NATO allies are already implementing plans for a further military buildup on Russia’s borders, making future confrontations between aircraft and ground forces not only highly likely, but inevitable.

Just a day prior to the Black Sea incident, NATO Secretary General Jens Stoltenberg announced that NATO would step up its presence in the Black Sea. Following a NATO-Georgia Commission meeting in the Georgian capital, Tbilisi, Stoltenberg held a joint press conference with Georgian Prime Minister Giorgi Kvirikashvili in which he blamed Russia for aggression in three areas: the Baltic, the Eastern Mediterranean and the Black Sea. “We have seen an increased Russian presence in the Black Sea region and we have also seen a substantial military build-up in Crimea by Russia,” Stoltenberg claimed.

Stoltenberg said military planners were drawing up proposals for a greater military presence in the region. While Georgia and Ukraine are not NATO members, Stoltenberg made clear that their status as NATO “partners” meant they would be fully involved. “For NATO and NATO allies, it is important to have close contact with partner countries like Ukraine and Georgia—being non-NATO members but NATO partners—and to dialogue with them regarding our increased presence in the Black Sea,” he stated. This will be a further provocation to Russia, which firmly opposes the integration of Kiev and Tbilisi into the US-led alliance.

Discussions were held at the Warsaw summit on increasing NATO’s presence in the Black Sea, where Russia’s naval fleet has been based since the collapse of the Soviet Union. NATO members Romania, Bulgaria and Turkey pressed for a permanent NATO naval presence, a move which would likely breach international law because of a treaty known as the Montreux Convention which commits all states that do not border the Black Sea to deploy military forces there for no more than 21 days.

NATO’s escalation of tensions in the Black Sea comes just two months after it unveiled the deployment of 4,000 soldiers to the Baltic republics and Poland, backed up by a rapid reaction force of some 40,000 troops capable of reaching the region in days. Missile defense systems are also planned for installation in Romania and Poland.

If Europe is not the scene of the next flashpoint between Washington and Moscow, it will most likely be a clash in Syria. Talks between Obama and Putin on the sidelines of the G20 summit broke down earlier this week without an agreement being reached on military cooperation against ISIS and other Islamist extremist groups, many of which have been funded by the US in its regime-change war against the government of Bashar al-Assad. US officials cited the failure to make progress on Washington’s “long-term” goals as the reason for the stalling of the talks. In other words, Moscow has failed to acquiesce to the installation of a pro-Western puppet regime.

Speaking to the BBC after his Oxford University speech, Carter repeated his denunciation of Russian aggression and vowed he would not support military cooperation with the Kremlin in Syria until it stopped attacking “US-backed interests,” according to ABC News.

The US backing for the Turkish incursion into northern Syria has placed NATO troops on the ground and more aircraft in the skies under conditions where Russia has intervened to prop up its most important Middle Eastern ally. With calls from Turkey in particular for the creation of a “safe zone,” a pretext used time and again to justify imperialist wars over recent decades, or a direct ground assault on ISIS strongholds with NATO backing, the potential for a direct conflict between NATO and Russian forces is increasing daily.