Free Syrian Army fighters and an American military vehicle at the US base at Tanf, in eastern Syria near the Iraqi border (File)

Continuing their pushback of Donald Trump’s impulsive order for withdrawal, the US military announces that at least 400 troops will remain in Syria.

On December 14 Trump decided on the withdrawal during a phone call with Turkish President Recep Tayyip Erdoğan.

Trump was prompted by the statement of Erdoğan, hoping to detach the US from the Kurdish-led force which Washington backs in Syria, that the Islamic State is “99% defeated”. He insisted on issuing a December 19 order, leading to the resignation of Defense Secretary and retired four-star general Jim Mattis and of Brett McGurk, the US envoy to the anti-Islamic State coalition.

But the US military and leading Trump officials still view ISIS as a threat. They also see the American presence in Syria as a counter to Iran, which provides essential military, political, and economic support for the Assad regime. And they are concerned that Turkey — which views the US-backed Kurdish militia YPG as “terrorists” linked with the Turkish Kurdish insurgency PKK — will attack and occupy part of the 27% of Syria held by Kurdish factions.

So the Pentagon and officials such as National Security Advisor John Bolton have extended the timeline for any American departure, now putting it at four to six months. None of the US troops have been withdrawn.

They have been buttressed by difficulties with any alternative to Syrian positions. When Trump said troops could be put in western Iraq to keep an eye on ISIS, Iraqi lawmakers vigorously objected and threatened steps to remove all American personnel from the country.

France and Britain rejected a US request to leave their forces in Syria amid a complete American withdrawal.

The White House backed away on Thursday with the announcement by Press Secretary Sarah Sanders of “a small peacekeeping group of about 200” troops remaining in Syria. She said it followed another phone call between Trump and Erdoğan.

A US official said half of the personnel will stay alongside the Syrian Democratic Forces, created in autumn 2015 to push out ISIS, in northeast Syria. Half will man the US base at Tanf, in eastern Syria near the Iraqi and Jordanian borders.

The official said the total might rise slightly.

If implemented, the step would bring the US deployment well above its official level of December 2016, at the end of the Obama Administration, when there were 286 declared personnel in Syria.

Sen. Lindsey Graham, a Trump ally who has led criticism of the withdrawal, said Thursday that the maintenance of US personnel in Syria force will “ensure that ISIS does not return and that Iran does not fill the vacuum that would have been left”. He also said that the steps means Turkey and Syrian Kurds “will not go into conflict”.

Reinforcing the impression that he has pressed the Pentagon’s case with the White House, Graham said, “With this decision, President Trump has decided to follow sound military advice.”