A senior Pentagon planning officer expects the current US air strikes in Iraq to have minimal and fleeting impact on the forces of the Islamic State (Isis) that have overrun much of the country.



“In the immediate areas where we have focused our strikes, we’ve had a very temporary effect and we may have blunted some tactical decisions to move in those directions, further east to Irbil,” Army Lt Gen William Mayville told reporters on Monday, providing a dour view of the “limited strikes” president Barack Obama authorized on Thursday.

“What I expect Isil to do is to look for other things to do, to pick up and move elsewhere. So I in no way want to suggest that we have effectively contained or that we are somehow breaking the momentum of the threat posed by Isil.” Isil is the acronym for Isis favored by the US government.

The air strikes, now in their fourth day and still something less than a concerted air campaign, have bought US-backed Kurdish irregular forces, known as Peshmerga, “time to fortify their defensive positions” outside the regional capital of Irbil, said Mayville, the director of operations for the Pentagon’s Joint Staff, and have slowed Isis’ advance toward the crucial city.

Beyond that, said Mayville, who commanded a brigade during the 2003 invasion of Iraq, the strikes “are unlikely to affect Isil’s overall abilities or its operations in other areas of Iraq and Syria”.

Mayville, briefing Pentagon reporters, provided a markedly downcast assessment, notable coming from a military better known over the past 13 years for confidently predicting success in Iraq and Afghanistan. He spoke shortly before Obama was scheduled to issue remarks on Iraq.

As has been long predicted by military critics of a bombing campaign, Mayville said Isis was already changing its tactics in response to the air strikes, particularly around Mt Sinjar, where on Saturday US warplanes attacked Isis positions surrounding the mountain where tens of thousands of Iraqi Yazidis have taken a tenuous refuge.

“Where they have been in the open, they are now starting to dissipate and to hide amongst the people, so the targeting of this – of those forces trying to effect a siege around the mountain – the targeting of this is going to become more difficult,” he said.

In the days after Isis overran Mosul and began its push into Iraq, the Pentagon had examined a bombing plan to target Isis positions in both Iraq and Syria, where the group first arose. Mayville gave no indication that plan or related plans would be put into effect.

“There are no plans to expand the air campaign beyond the current self-defense activities,” said Mayville, who described the Pentagon as “gripped with the immediacy of the crisis”.

The Obama administration formally considers air attacks on Isis near Irbil – the vast majority of the strikes thus far – to be taken in defense of US advisers, diplomats and other citizens in the Kurdish regional capital, although they also have the effect of acting as rough air cover for the Peshmerga, whom the US has now decided to directly arm for the first time.

Mayville described Isis as a high quality and impressive adversary, a description that has almost never been provided by senior Pentagon officials about the assortment of terrorist groups, militias and insurgents the US military has fought in Afghanistan, Iraq, Yemen, Somalia and elsewhere for the past 13 years.

“They’re very well organized, very well equipped, they coordinate their operations and they have thus far shown the ability to attack on multiple axes. This not insignificant,” Mayville told reporters.

While there is little appetite within senior ranks of the military for reinvading Iraq two and a half years after departing, deep frustration exists amongst Iraq veterans at the ease with which Isis has taken over much of the northern and central parts of the country. A less vocal frustration also exists with White House responses that some consider belated half-measures.

Speaking last week, David Deptula, a retired three-star air force general, told the Guardian that a “competent, coherent, holistic air campaign” would be effective against Isis. Thus far, the strikes launched appear to be responses to specific Isis advances toward Irbil and attacks on Peshmerga, or an attempt to end the siege of Mt Sinjar, rather than an air campaign targeting key Isis personnel, command nodes, supplies, logistics or territory.

Mayville also said that despite over 50 surveillance flights over Isis-dominated areas of Iraq, the US military had yet to prepare a plan, desired by Obama, to bring thousands of Yazidis down from the mountain and into safe passage. Kurdish forces helped bring several thousand Yazidis off Mt Sinjar on Sunday night, while Obama adviser Ben Rhodes assured that the administration was “reviewing options for removing the remaining civilians”.

The general praised the Kurdish Peshmerga, which the CIA, though not the Pentagon, is beginning to arm. Mayville said he viewed the Iraqi government’s decision to resupply Kurdish weapons and ammunition stocks as a positive sign, and said the Pentagon was “looking at ways we can expand that support”.