The US government said Saturday that soldiers in the elite Delta Force, the main Pentagon Special Forces unit, had carried out a raid into eastern Syria, killing a leader of the Islamic State in Iraq and Syria (ISIS) and other members of the Islamic extremist group.

The Pentagon identified the high-level ISIS official as a Tunisian who had assumed the name Abu Sayyaf (Arabic for "father of the sword"). According to the US government, when he fought back against the attacks, the commandos killed him and a dozen other men, before returning to Iraq with two female captives.

President Obama gave the order for the raid, the White House said, based on the "unanimous recommendation" of US national security officials, and with the consent of the Iraqi government of Prime Minister Haider al-Abadi for the use of Iraqi bases to launch the attack inside Syria.

US press coverage supplemented the brief announcement by Secretary of Defense Ashton Carter, giving details of the raid supplied in unattributed interviews from Obama administration officials in both the White House and Pentagon.

By these accounts, US Huey helicopters and Osprey vertical takeoff planes transported the Delta Force commandos from a base in Iraq to the location at al-Amr, the largest Syrian oil field, about 20 miles south of Deir el Zour in the eastern desert.

The commandos allegedly encountered resistance when they attempted to seize Abu Sayyaf and his wife, and killed him and a dozen other ISIS fighters, before retreating under fire to their aircraft and returning to Iraq with two women: Umm Sayyaf, the ISIS leader's wife, and a Yazidi woman in their household. The US troops suffered no casualties despite the supposedly fierce firefight and "hand-to-hand" combat.

Weekend news reports in the United States were devoted to celebratory accounts of the raid and the daring of the Special Forces commandos, the "courage" of Obama in ordering the attack, ad nauseam, with no discussion of the likely consequences of such military actions becoming more frequent in the future.

None of the details provided in the press accounts can be accepted as fact, given that the US officials refused to provide details that could be independently verified. Such anonymous leaked accounts have been used to plant false reports, most notoriously in relation to the May 1, 2011 commando raid that killed Al Qaeda leader Osama bin Laden.

A lengthy expose by veteran investigative reporter Seymour Hersh, published May 10 by the London Review of Books, argued that virtually every detail of the raid that killed bin Laden was falsified by US official spokesmen, from President Obama on down.

Similarly, the claims about Friday's raid should be treated as entirely unproven at this stage. The US government has admitted that its troops entered Syria without notifying the government of that country, making its operations there completely illegal under international law. Anything beyond that remains to be demonstrated.

Syrian official television initially claimed that the raid was conducted by forces loyal to President Bashar al-Assad, not those of the United States, and that five leaders of ISIS were among the dead, including a Tunisian, a Chechen, a Turk, a Saudi and an Iraqi.

The White House adamantly denied the Syrian claim. National Security Council spokeswoman Bernadette Meehan told reporters, "The US government did not coordinate with the Syrian regime, nor did we advise them in advance of this operation."

Meehan continued, using a different acronym for Islamic State, "We have warned the Assad regime not to interfere with our ongoing efforts against ISIL inside of Syria. The Assad regime is not and cannot be a partner in the fight against ISIL."

This statement has ominous implications. What will happen if US forces come into contact with Syrian government forces during future operations like Friday's raid? There is every reason to believe that a major purpose of such incursions into Syrian airspace and Syrian territory is to create a pretext for a direct US attack on the Syrian army and the Assad government.

There was some substantiation of at least part of the Syrian television account of the raid on the al-Amr oilfield. The Syrian Observatory for Human Rights, a group hostile to Assad and aligned with efforts to promote foreign intervention in Syria to overthrow the regime, reported that the US special forces raid killed 32 ISIS fighters, including four leaders, identifying them as "IS oil chief Abu Sayyaf, the deputy IS defence minister, and an IS communications official."

This puts the death toll at much higher than reported by the Pentagon, and confirms the Syrian claim that a group of ISIS leaders, not just one, were killed.

The exact circumstances of the raid may not be known for some time. But the political context in which it takes place suggests a significant escalation by the Obama administration.

The raid is the fourth US special forces operation in the Middle East in less than a year, including an unsuccessful raid last summer on an ISIS facility in Raqqa, allegedly to rescue US hostages who were later executed, and two unsuccessful raids in Yemen in November and December, supposedly to rescue an American held prisoner by Al Qaeda in the Arabian Peninsula (AQAP). The American AQAP prisoner and a South African fellow captive were killed during the second raid.

Meanwhile, US-led airstrikes on ISIS targets across eastern Syria continue. In the 24 hours ending Sunday morning, the Pentagon reported eight bombing attacks, including six near the city of Hasakah, in the northeast, and two near Kobani, a Kurdish-populated town where a lengthy ISIS siege was broken by US saturation bombing.

In an editorial published May 13, the Washington Post urged the Obama administration to openly declare the goal of its intervention in Syria to be the overthrow of the Assad government. Pointing to the mounting disagreements between Obama and the Gulf sheikdoms, reflected in the near-boycott of last week's Camp David meeting by four of the six Gulf monarchs, the Post declared, "But there is a way that Mr. Obama could serve both US interests and those of the Gulf allies: by attacking the Middle East's most toxic and destabilizing force, the Bashar al-Assad regime in Syria."