The US military command responsible for fighting the Islamic State has signaled it will retain one of the cornerstones of the Obama administration’s approach to the war, even as Donald Trump considers an escalation of the conflict.

With Iraqi forces, aided by American airstrikes and artillery, closing in on the Isis redoubt of western Mosul and an anticipated battle for Isis’s Syrian capital of Raqqa looming in the near future, the command indicated on Wednesday that it expects to hew toward relying on local proxies on the ground for the lion’s share of the fighting.

That approach, known as “By, With and Through”, has limited direct US combat to the hundreds of special operations troops, mostly in Syria, whom Barack Obama formally designated as “advisers” – and accordingly has kept US troop deaths low.

But it has also come under criticism for outsourcing the pacing of the war to Iraqi soldiers, Iranian-supported militias and fractious groups of Syrian rebels, some of whom have alarmed Nato ally Turkey and whose agendas can diverge from those of the United States.

While James Mattis, the US defense secretary, is expected to deliver to Trump a set of options for expanding the conflict against Isis as early as next week, the Baghdad-based military command conducting the war indicated that By, With and Through will remain a keystone of the war’s conduct.

The battle for Mosul: a dirty war in Isis's heartland – video Read more

“One of the things that General [Stephen] Townsend has been very clear on is that we’re working by, with and through the Iraqi security forces in Iraq and then our partners in Syria. That fundamental principle isn’t going to change,” Colonel John Dorrian, the chief spokesman for the war, said on Wednesday.

Townsend, Dorrian said, would not hesitate to ask for new troops, new hardware or new authorities as necessary.

Dorrian confirmed that Townsend had made recommendations for accelerating the war against Isis to Gen Joseph Votel, the head of US Central Command, who has relayed them to Mattis for deliberation. But he did not provide any detail on what Townsend had requested.

Votel, speaking from Jordan on Wednesday, said that one option to speed up a long-signaled attack on Raqqa was to “take on a larger burden ourselves”. Shouldering more of the task would mean US forces, conventional as well as special operations, bringing more artillery and logistics options to the fight. Votel did not indicate that Americanizing the fight for Raqqa was an option under active consideration.

Andrew Exum, a senior Pentagon Middle East policy official during the final years of the Obama administration, said it was more likely that conventional US forces would aid an impending Kurdish-led assault on the city than that the US would restructure its approach to the war wholesale.



“By, With and Through wasn’t something the civilians in the Obama administration came up with. It’s the core principle of the US military’s coalition campaign plan. This is something the military leadership is invested in, and even though the Obama administration has departed, the uniformed military leadership is still there,” Exum said.

In western Mosul, the final stronghold Isis possesses in Iraq, the fight is already under way – led by Iraqis and assisted by airstrikes and powerful Himars mobile artillery from their US allies. Dorrian said that US troops in the city have come under fire from Isis, where he estimated between 1,000 and 3,000 fighters remain, and returned it.

On the campaign trail, Trump falsely claimed that he had a secret “foolproof” plan to defeat Isis and that he knew more about the group than did US generals. Upon his election, the secret plan vanished and gave way to an executive order in late January instructing the Pentagon, intelligence agencies and relevant cabinet departments to undertake a 30-day review of the war effort in order to construct a new plan.

Christopher Harmer, a former navy officer and defense analyst at the Institute for the Study of War, said the US had few options for conducting the war outside of By, With and Through.

“The only way for us to have success in Iraq is if we work by, with and through the established Iraqi security forces. The US military spent a tremendous amount of time and effort establishing the post-Saddam Iraqi security construct, so we have to work through them if we ever expect the Iraqi government to be seen as even nominally self-sufficient,” Harmer said.

In Syria, he said, “the only viable option for maneuver warfare for the foreseeable future is Kurdish militia, and Turkey would rather see the Syrian civil war continue than Kurdish forces get credit for defeating Isis in Syria.”