US military forces in Iraq will take on a more direct combat role once US-backed national and local forces have reconquered territory now controlled by the Islamic State in Iraq and Syria (ISIS), US Defense Secretary Ashton Carter said Thursday during an address to US troops in Baghdad.

Carter’s visit is part of preparations for another escalation of combat operations in Iraq, relying on an array of proxy forces, in an effort to consolidate Washington’s military grip over the country.

Carter began his unannounced one-day visit with an appearance at the Iraqi Counterterrorism Service Academy, a training center for elite Iraqi commando units. The academy was originally formed by the US occupation authorities, and US officials say that the forces trained there will lead an upcoming assault against Ramadi, which ISIS captured in May and which is currently held by some 1,000-2,000 of its fighters.

The offensive will be carried out under the close supervision and direction of US military “advisers,” Pentagon officials said this week.

Carter also received briefings from Iraqi officials on efforts to train additional units for the US-backed force, which maintains close ties to the US military and has undergone extensive training at US-run programs in Jordan.

The US defense secretary looked on as the Iraqi commandos, decked out in paramilitary gear, their faces covered with black masks, practiced troop maneuvers and live-fire target practice, according to the New York Times .

In contrast to his remarks earlier this year that regular Iraqi government forces “lacked the will to fight,” Carter lavished praise on the US-supported Iraqi Counterterrorism Service (ICTS).

“Your forces have performed so very well, so very bravely,” Carter said. “And I know that you have suffered great losses too, but I just wanted to tell you that it is very clear to us in Washington what a capable force this is. So it’s a privilege for us to be your partners.”

These same “brave” and “capable” partners have been implicated in atrocities against civilians. Photos published by ABC News earlier this year showed the US-trained Special Forces troops posing with corpses and severed heads.

Along with an assortment of government troops and militias, including thousands of Iraqi regulars and federal police forces, the Iraqi Special Forces troops are preparing to lead the attack on Ramadi.

“When conditions are right, we will transition into an assault to seize Ramadi,” US Army spokesman Colonel Steve Warren said Thursday. “We are beginning to isolate Ramadi from multiple directions,” he added. “We are beginning to put a noose around the city.”

Additional hundreds of Sunni tribal forces mobilized by the US are expected to support the assault. The Sunni forces will be tasked with holding Ramadi and the surrounding territory after ISIS is driven out, US military officials said.

These Sunni tribal elements will participate in the operations as an autonomous force, not subject to the central Iraqi command structure, according to US officials.

“They are essentially operating together, but without a strict and formalized command and control relationship being established,” Warren said.

US imperialism is seeking to promote the Sunni militias as a means of deepening its penetration of Iraqi society and gaining leverage over the Iranian-backed central government. Just as during the 2003-2011 US occupation, American imperialism is striving to maintain its stranglehold over Iraq through the stoking up of sectarian divisions and the mobilization of tribal-based militias.

President Obama vowed in May that Washington would take steps to “get the Sunni tribes more activated.”

During congressional testimony last month, Carter threatened that the US has prepared a strategy to dissolve the unified Iraqi state if Washington deems it necessary, bypassing Baghdad and instead ruling portions of the country on the basis of separate alliances with Sunni and Kurdish elements.

In light of these remarks, Carter’s euphemistic calls for “inclusive governance” in Iraq, issued during a joint appearance with Iraqi Prime Minister Haider al-Abadi from inside the militarized “Green Zone” in Baghdad, were clearly intended to signal that the US will not tolerate hostility by the central government to the political aspirations of US proxy forces opposed to Abadi’s Shia-led regime.

The offensive being planned in Anbar is viewed by Washington as a trial run for a further expansion of US involvement in the ground war raging across large areas of the country.

The US Defense Department is preparing for possible deployment of hundreds or even thousands of more troops to Iraq in the coming year, as part of a “lily pad” strategy based around a new network of US bases, General Martin Dempsey said last month.

Any further deployments will come on top of more than 10 months of continuous ground and air operations, involving some 3,600 US ground troops and a continuous aerial bombardment by the US-led coalition.

The continued vitality of ISIS, which succeeded in seizing control of Ramadi with a relatively minuscule force of lightly armed fighters, has fueled already widespread suspicions among Iraqis that Washington is, in fact, “resupplying” ISIS and that US planners are not especially concerned about defeating the group.

Such suspicions are entirely justified. ISIS emerged out of the US-engineered war in Syria, where the Pentagon and Central Intelligence Agency financed and equipped an insurgency led by Islamist militants, as part of their efforts to topple the government of President Bashar al-Assad.

Even as it fomented civil war against the Syrian government in Damascus, the US military-intelligence apparatus was fully aware that extremist groups, including Al Qaeda in Iraq (AQI), were leading the war against Assad and seeking to establish an Islamic state in eastern Syria, the release earlier this year of secret intelligence report by the Defense Intelligence Agency (DIA) confirmed.

Despite the humiliating blows the group has delivered to US-trained government forces in Iraq, ISIS continues to serve as a useful cat’s paw for US imperialism’s machinations on both sides of the Iraq-Syria border. It has become the central pretext for a much broader escalation of the US “war on terror” across large areas of Africa and Asia, and within the US itself.