Speaking about the crisis in Syria on BBC’s Newsnight, David Frum said that the militants, who currently control swathes of land across Iraq and Syria, are not the West’s most important strategic threat in the region but ‘that is Iran.’

Frum said “Our [America’s] focus on the Islamic State… has been leading us into a de facto partnership with Iran.”

This was “protecting the larger strategic threat at the expense of the lesser strategic threat,” he said.

Meanwhile a number of regional experts and U.S. officials have warned that the United States should beware of the perils of collaborating with the Iranian regime in the fight against ISIS terror group.

According to one expert, in the long term, Shiite militias that are backed by Iran could provide the regime with opportunities to set up Hezbollah-like groups to spread Tehran’s ‘radical ideology more intensively’ and project their power into Shiite communities worldwide.

US officials have said that Shiite militias have been fighting IS, but that there have also been reports of them working with Iraqi security forces to target Sunnis.