This is horrible from two perspectives. First, we are abandoning a staunch ally in the region. Second, it further encourages Iran to be belligerent against Saudi Arabia and Israel to test America’s resolve to support our allies.

US troops have begun withdrawing from positions in northern Syria, paving the way for a Turkish operation against Kurdish fighters in the border area.

Kurdish-led forces have until now been a key US ally in Syria, where they helped defeat the Islamic State group, but Turkey regards them as terrorists.

The main Kurdish-led group called the surprise US move a “stab in the back”.

But President Donald Trump defended the pullout, saying it was time “to get out of these ridiculous Endless Wars”.

The withdrawal represents a significant shift in US foreign policy and goes against the advice of senior officials in the Pentagon and state department. It follows a White House statement issued late on Sunday, saying US troops were stepping aside for an imminent Turkish operation.