The threat of all-out war between Russia and the NATO military alliance increased on Wednesday, the day after Turkish F-16 fighters shot down a Russian Su-24 bomber along the Syria-Turkey border in a blatant act of aggression.

The action, backed by President Barack Obama on Tuesday, was a blunt signal to Moscow that Washington opposes its intervention in Syria to prop up President Bashar al-Assad, and is willing to risk war with Russia to stop it.

The decision to destroy the Russian jet was taken at the highest levels of the Turkish state. At a meeting of Turkey’s ruling Justice and Development Party (AKP) yesterday, Prime Minister Ahmet Davutoglu took credit for giving the order that led to the shooting down of the Su-24. He said that after tensions with Russia over alleged violations of Turkish air space last month, he issued a standing order to shoot down any aircraft violating Turkish air space. In effect, the top level of the government gave a blank check to the military to fire on Russian planes operating against Islamist opposition militias along the Syrian-Turkish border.

There is little doubt that the decision to make such a standing order would have first been carefully discussed with Washington, and possibly other leading members of the NATO alliance.

By giving the Turkish army a green light for unprovoked acts of war against Russia, the AKP knew it risked a conflict in which it would need NATO and, in particular, US support. A situation where Turkey started a war with Russia but was disavowed by its European and North American allies would have left it exposed to military annihilation.

In the event, Obama and NATO Secretary General Jens Stoltenberg supported Turkey’s aggressive action against Russia. Speaking for the entire NATO alliance, Stoltenberg endorsed Turkey’s action, stating: “As we have repeatedly made clear, we stand in solidarity with Turkey and support the territorial integrity of our NATO ally, Turkey. We will continue to follow the developments on the south-eastern borders of NATO very closely.”

The Obama administration backed the Turkish government’s reckless action in line with the basic geopolitical interests of US imperialism, which bring it into conflict with Russia and, increasingly, with the European powers over Syria. Washington opposes Russian intervention in Syria because the US supports the Islamist opposition forces backed by Turkey, and aims to topple the Assad regime that Moscow is backing. Obama bluntly warned Moscow on Tuesday that the US opposed Russian air strikes on Islamist militias in western Syria, where the Su-24 was shot down.

Moreover, Washington opposes the French government’s attempt, after the November 13 attacks in Paris by the Islamic State in Iraq and Syria (ISIS), to build a coalition to fight Islamist terrorist groups in Syria, including both Moscow and Washington. In fact, Washington relies critically on the Islamist militias—as it has from the beginning of the Syrian war in 2011—as proxy forces on the ground against Assad.

These concerns were aired in a comment piece prepared Tuesday by the Center for Strategic and International Studies (CSIS), a Washington think-tank with close connections to the US military and intelligence apparatus.

Heather Conley, senior CSIS vice president for Europe, Eurasia and the Arctic, criticized French President François Hollande’s plan to bring together an alliance involving both the United States and Russia against ISIS after the Paris attacks. “The Syrian conflict has become a multi-layered proxy war under the auspices of a coalition of the disingenuous,” she wrote.

The CSIS dismissed attempts by the Obama administration to “de-conflict” relations with Russia, by coordinating military action in Syria with Moscow, as contrary to US interests. It complained: “In practice this has amounted to the Kremlin directing the United States to halt operations in Syria while it conducts its own airstrikes (something Washington has refused to do), suggesting the limitations of these communications and the ability to de-conflict.”

Conley added that the impact of the shooting down of the Russian jet would be to block efforts by France and other European powers to reach an agreement with Russia on policy in Syria. “Today’s events suggest it is now impossible to hide the fact that the presumed members of this envisioned coalition are actively working at military and political cross-purposes with deadly consequences.”

Conley concluded by turning reality on its head, threatening Russia by insisting that it “return to its adherence of international legal norms and fully respect the principle of territorial integrity.” It is in fact the United States that has invaded country after country with the aim of asserting control of the Middle East, including the stoking of civil war in Syria.

The aggressive policies of Washington and Ankara threaten to provoke an escalation into all-out nuclear war. Russian Foreign Minister Sergei Lavrov delivered a statement that, while it declared that Russia would not go to war with Turkey, accused the United States of complicity in the attack.

Lavrov said the incident “looks very much like a pre-planned provocation” and indirectly pointed to American responsibility, noting that Washington asks its allies using US-made military aircraft in Syria to coordinate their movements with US forces. He said: “I wonder if this demand of the Americans covers … Turkey. If it does, I wonder whether Turkey asked permission from the US to fly its US-made planes and take down—let’s say an ‘unidentified’—plane over Syrian territory.”

Lavrov also cited the remarks on Tuesday of NATO chief Stoltenberg, saying: “Very strange statements were voiced after a NATO meeting called by the Turks, which didn’t express any regret or condolences and in effect were aimed at covering up what the Turkish air force did yesterday. A similar reaction came from the European Union.”

Lavrov again denied that the Russian plane violated Turkish airspace, but added that if it briefly did so, this would not justify shooting it down. He cited 2012 remarks by then-Turkish Prime Minister Recep Tayyip Erdogan (now president), who denounced a Syrian decision to shoot down a Turkish fighter in Syrian airspace, saying that a brief incursion could not justify an attack.

Captain Konstantin Murakhtin, the surviving member of the two-man crew of the downed Su-24, also refuted Turkish claims that the Su-24 violated Turkish airspace and ignored warnings to turn back into Syria.

“In actual fact, there were no warnings at all. Neither through the radio, nor visually, so we did not at any point adjust our course. You need to understand the difference in speed between a tactical bomber like a Su-24, and that of the F-16. If they wanted to warn us, they could have sat on our wing.” Murakhtin said. “As it was, the missile hit the back of our plane out of nowhere. We didn’t even have time to make an evasive maneuver.”

At the same time, Moscow has launched a substantial military build-up in Syria and the eastern Mediterranean and cut off all military communications with Turkey. This underscores the bankrupt and reactionary character of Russian foreign policy, which veers between capitulation to the NATO powers’ demands and reckless measures posing the risk of world war.

Russia is rapidly boosting its air defense forces in Syria and the eastern Mediterranean. It announced that it would deploy an S-400 air defense system to its airbase near the Syrian city of Lattakia. This is a high-tech missile system capable of detecting and shooting down planes in a wide area that, from its base near Lattakia, includes much of southern Turkey. Such a system could have responded to the destruction of the SU-24 jet by shooting down the Turkish F-16s that attacked it.

The deployment followed the announcement Tuesday that the Russian air defense cruiser Moskva had arrived in the eastern Mediterranean. State broadcaster Russia Today announced that the ship is “ready to take down any aerial targets … with long-range surface-to-air missiles.”