American warplanes launched an attack on pro-government forces in southeastern Syria Thursday, near the borders with Iraq and Jordan. The attack is the first time since the April 6 cruise missile assault on the al-Shayrat air base that the US military has targeted forces loyal to Syrian President Bashar al-Assad.

According to the US version of events, the fighters violated a deconfliction zone by advancing to within 18 miles of the al-Tanf base, where US and British special forces have been training Sunni militants for over a year. This military action is in blatant violation of international law since the Western forces have not been invited onto Syrian territory by the Assad government.

The actions of the pro-government forces “posed a threat” to partner forces, the US-led coalition said in a statement.

The forces involved appear to be a paramilitary group aligned with Assad. The Syrian military reported that six personnel were killed and three injured in the attack, according to the al-Masdar News agency.

According to the US-led coalition’s statement, after performing a “show of force” by flying low over the area and firing a warning shot, the US planes struck a tank, a bulldozer and fighters.

But in contrast to the US version of events, a Damascus-based political analyst, Alaa Ibrahim, told RT that according to Syrian military sources, the paramilitary group never received any warning prior to the strike.

There was no indication that the pro-government fighters posed an immediate threat to US troops. The US military statement merely noted that the Syrian fighters were engaged in constructing fighting positions when the aircraft struck. It added that they clashed with the Pentagon-backed Maghawir al-Thawra militant group, formerly known as the New Syrian Army.

The reality is that the Islamist forces being trained by the US are part of its regime change operation against Damascus, which Washington has been pursuing since it fomented the Syrian civil war in 2011. Its ordering of a strike on pro-government forces underscores the deepening tensions as both sides in the conflict scramble to seize territory from Islamic State in the east of the country so as to strengthen their hand in the struggle for control over Syria.

Washington has swiftly stepped up its intervention in Syria since the coming to power of Donald Trump in January. Thursday’s strike marks the second time in less than six weeks that Washington has directly targeted Assad’s forces, following the April 6 cruise missile assault on the al-Shayrat air base in retaliation for the alleged chemical weapons attack by the Assad regime in Khan Sheikhoun two days earlier.

The number of ground forces operating in the country has been more than doubled and Trump has untied the military’s hands by loosening the rules of engagement for air strikes, resulting in a spike in civilian casualties. In the latest atrocity, at least 40 civilians were killed and many more wounded by a suspected US-led coalition air strike in Deir ez-Zor.

The US escalation carries with it the threat of a direct clash with nuclear-armed Russia, which intervened into the Syria conflict in 2015 to prop up its sole ally in the Middle East region. Although US officials maintained they had contacted the Russians prior to the air strike yesterday, this does nothing to take away from the fact that Washington and Moscow are working at cross purposes in Syria.

Washington is in a tacit alliance with ISIS insofar as the Jihadi group continues to attack government-controlled areas. As the US focused attention on the purported “threat” posed by the pro-government fighters near al-Tanf Thursday, ISIS launched a significant offensive in the central region, capturing a village and killing dozens of Syrian soldiers.

US officials showed no concern for the reports of beheadings and removal of limbs from women and children by ISIS in the predominantly Shia villages captured. At least 52 people, including 11 women and 17 children belonging to the Ismaili branch of Shia Islam, were killed in the violence in Hama province. The attack occurred near the highway linking Damascus to the northern city of Aleppo, from where pro-Assad forces expelled US-backed Islamists last December.

Rami Razzouk, a coroner at the national hospital in Salamiyeh, told AP that nine of the children were beaten to death with heavy objects and two of them “had most of their limbs removed so they had to be carried in blankets.”

There were no reports of air strikes launched by the ostensible anti-ISIS international coalition in the area to curb the Islamist militia’s advance.

This should come as no surprise. During the 2011 bombardment of Libya to oust the Gaddafi regime, US imperialism gave its backing to Islamist extremist forces, many of whom were subsequently funneled, with the assistance of the CIA, into Syria to act as the backbone of the rebel forces fighting Assad. Some of them united to form ISIS with disaffected Sunni elements in Iraq, who had been radicalized by Washington’s deliberate incitement of sectarian tensions in the wake of its illegal 2003 invasion.

Indicating the mounting rivalries between US imperialism and the other powers involved in Syria, the Financial Times reported earlier this week that the latest ceasefire arrangement agreed in Astana May 4, which included a deal to stop fighting in four de-escalation zones, is being viewed by all parties as a mechanism to accelerate the partition of the country. A buffer zone in the south close to the Jordanian border, which would include the al-Tanf base from where the US and British special forces are training Islamist rebels, could become the basis for a push by the US proxies to cut off Iranian supply lines through the east of Syria. One diplomat told the FT that “the race now is to get the biggest share.”

The US-backed Syrian Democratic Forces (SDF), which is dominated by the Kurdish People’s Protection Units (YPG), is advancing on the ISIS capital of Raqqa. The Trump administration’s authorization of the provision of heavy weaponry to the SDF last week, over the strenuous objections of NATO ally Turkey, is aimed at preparing an all-out offensive to retake the city which will reportedly be launched in the coming weeks. The consequences of such an assault for the civilian population will be disastrous, as can be seen in the Iraqi city of Mosul where thousands of civilians have been slaughtered in indiscriminate air strikes and shelling by the Iraqi army.

Thursday’s US strike on pro-Assad forces will make it even less likely that any significant progress will be attained at the ongoing sixth round of peace talks, which began in Geneva on Tuesday. Already on the eve of the negotiations, the State Department issued lurid and unverified allegations about the operation by the Assad regime of a crematorium at the Sednaya prison near Damascus in a move designed to undermine the UN-sponsored initiative.

Discussions on a future constitution for the country broke down Thursday as opposition groups requested clarification on a proposal that would have seen a UN commission, under the leadership of the UN’s Syria envoy Staffan di Mistura, oversee a transition process following a peace agreement.