Fighting raged in northwestern Syria as Turkey’s “Operation Olive Branch” completed its third day Monday. Turkish special forces troops and Turkish-backed Islamist militiamen of the so-called Free Syrian Army opened up a second front in their assault on the Kurdish enclave of Afrin, advancing from the town of Azaz to the east. The apparent aim is to drive forces of the Syrian Kurdish YPG militia south and away from the Turkish border. Intense fighting had previously been reported between advancing Turkish forces and YPG fighters for control of two villages northwest of the city of Afrin.

This new front in the seven-year-old war that was launched as a regime-change operation backed by both Washington and Turkey, along with Saudi Arabia and the other Persian Gulf oil monarchies, has threatened to disrupt US imperialism’s military strategy in the region, while exacerbating already sharp tensions within NATO and between the US and Europe.

The offensive, which is being carried out against elements of a Kurdish militia that has served as Washington’s main proxy ground force for its intervention in Syria, marks a new low point in relations between the ostensible NATO allies, the US and Turkey. These ties had already been severely strained over Ankara’s rapprochement with Russia, from which it is buying advanced air defense systems, over NATO’s objections, and charges that Washington provided covert backing to an abortive 2016 coup against the government of President Recip Tayyip Erdogan.

The White House issued a statement Monday warning that the Turkish offensive “distracts from international efforts to ensure the lasting defeat” of Islamic State of Iraq and Syria (ISIS). With ISIS already crushed in both Iraq and Syria, what Washington really means is that the Turkish action disrupts US efforts to assert its hegemony over the region and destroy the influence of Russia and Iran.

As the National Defense Strategy document released by the Pentagon last week made clear, the US military’s priority is no longer the so-called war on terrorism, but rather preparation for “great power” confrontation, including war with both Russia and China.

The White House statement went on to declare that Washington was urging “Turkey to exercise restraint in its military actions and rhetoric; ensure that its operations are limited in scope and duration; ensure humanitarian aid continues; and avoid civilian casualties.”

The statement was slightly more pointed than earlier remarks by US Secretary of State Rex Tillerson and Defense Secretary James Mattis. Tillerson, speaking in London, also urged “restraint,” but appeared to legitimize the Turkish invasion, stating, “We recognize and fully appreciate Turkey’s legitimate right to protect its own citizens from terrorist elements that may be launching attacks against Turkish citizens and Turkish soil from Syria.”

The depth of the ongoing crisis was indicated by a reporter’s question of whether the Syrian conflict could become a direct military confrontation between two NATO members. “I don’t think you’re going to find two NATO allies facing off at all,” Tillerson replied.

Similarly, Mattis stated that “Turkey has legitimate security concerns,” adding that Ankara “warned us before they launched the aircraft they were going to do it, in consultation with us.”

NATO echoed the US position in a statement that could only have been issued with Washington’s approval. “Turkey is situated in a volatile region, and has suffered significantly from terrorism,” it said. “All countries have a right to self-defense, but it’s important that this is done in a proportionate and measured way.”

US officials have even sought to distance themselves from the Kurdish force in Afrin, claiming that it is not the same as the Kurdish militia that it has armed and supported in northeastern Syria. This is pure sophistry, exposed by the fact that leaders of the Syrian Democratic Forces, the umbrella group for the YPG-dominated US proxy force, have discussed sending reinforcements from the east to Afrin to oppose the Turkish invasion.

US appeals for restraint appeared to have little effect upon President Erdogan, who responded with a blistering statement during an appearance in Ankara Monday. Turkey would “not take a step back” from its military operation in Afrin, he declared.

“The US is urging that the operation should not last too long and should be conducted within a certain time frame,” he continued. “I ask the US: Does your operation in Afghanistan, which you launched more than 10 years ago, have a certain time frame? When will it be completed? You are also still in Iraq, aren’t you? Do these kind of operations have a certain time frame?”

The Turkish president also said that the campaign in Afrin would be extended to Manbij, a Syrian town on the western side of the Euphrates River that was taken from ISIS by the YPG militia with the assistance of US special operations forces that are still deployed in the area. In an earlier speech on Saturday, the Turkish president vowed to “annihilate the terror corridor up to the Iraqi border,” and there were reports Monday of exchanges of fire across the border in eastern Syria.

Turkey’s declared aim is to create its own buffer zone extending 18 miles into Syria. Erdogan has also spoken of returning the 3.5 million Syrian refugees in Turkey to the zone, raising the specter of an ethnic-cleansing operation to remove the Kurdish population.

“One must be a fool not to understand that this treacherous project’s target is Turkey,” Erdogan said of the US use of the YPG. “They refused to give arms to us with money but they are giving weapons to the terrorist organization free of charge. Why are we strategic partners? Why are we strategic allies?”

The Turkish offensive was triggered by Washington’s announcement that it was building up a 30,000-strong border security force to take control of Syria’s northern border with Turkey and eastern border with Iraq, with the main forces being drawn from the YPG.

In the face of Turkish protests, Washington gave an unconvincing retraction, claiming that it was not building a border force, but was keeping its more than 2,000 ground troops in Syria indefinitely. The mission of this force includes continuing the war for regime change against the government of President Bashar al-Assad and countering the influence of Iran and Russia.

The Turkish daily Hurriyet reported Monday, “If US Secretary of State Rex Tillerson had given a clearer message in support of Turkey on Jan. 17, a day after his meeting with Turkish Foreign Minister Çavuşoğlu, things could have unfolded differently. The US’s apparent indifference to Turkey’s security concerns prompted Ankara to seek Russian support to act on what it perceives as an existential threat.”

Moscow has also blamed the Turkish action on the provocative US announcement of its proposed occupation of Syrian territory with a Kurdish-dominated border force. “Washington has actively encouraged and continues to encourage separatist sentiment among Kurds,” Russian Foreign Minister Sergei Lavrov said Monday. “This is either a lack of understanding of the situation or an absolutely conscious provocation.”

Erdogan said that his government had spoken about the Turkish offensive with “our Russian friends” and that “We have an agreement.”

While Moscow has not confirmed such a deal, it withdrew the small number of troops that it had on the ground in Afrin and has not opposed Turkish warplanes from bombing in skies over Syria that Russia has effectively controlled.

Turkey also reportedly used Moscow as a go-between in communicating its intentions to the Assad government. According to some reports, Ankara has offered to restore diplomatic relations, broken off in 2011, and to recognize the Assad government in return for a free hand on the Syrian border. It would appear that Moscow and Damascus are prepared to accede to Ankara’s reactionary aims as a means of countering Washington’s plans for carving out its own zone of control inside Syria.

Washington’s unilateral actions in Syria and elsewhere in the Middle East, combined with its increasingly bellicose threats of war against Russia, have also opened up a serious breach with its erstwhile Western European allies.

This divide was highlighted Monday with the simultaneous appearances of US Vice President Mike Pence before the Israeli Knesset, where he pledged that the US embassy would be moved to Jerusalem next year, and of Palestinian Authority President Mahmoud Abbas in Brussels before European Union minsters, who reiterated their support for Jerusalem as a “shared capital” as part of a so-called two-state solution.

The depth of the crisis of US imperialist policy in Syria found its unmistakable expression in the reaction of a section of the pseudo-left. A group of “activists” and academics, led by Noam Chomsky, professor emeritus of linguistics at the Massachusetts Institute of Technology (MIT) and the supposedly radical critic of US foreign policy, issued a statement condemning the Turkish action in Syria and the “inaction by the US to stop it.” The thrust of this appeal is for US imperialism to launch another war in the name of human rights, this time to assert its dominance over a challenge from a formal ally and de facto regional rival, that could lead to a massive escalation of the carnage in the Middle East.