Describing Iran as the “single, most significant threat” to regional stability, a top American commander today accused Tehran of carrying out “malign activities” in more than a dozen countries, including India.

As such an Iranian miscalculation raises the risk of sparking disastrous conflict, Commander of the US Central Command Gen. James Mattis told members of the powerful Senate Armed Services Committee during a Congressional hearing.

“Iran remains the single, most significant, regional threat to stability and prosperity. Reckless behaviour and bellicose rhetoric characterise a leadership that cannot win the affection of its own people or the respect of any responsible nation in the region,” Mattis said.

“Iran’s continued support to the murderous Assad regime in Syria coupled with its malign activities in Iraq, Lebanon, Afghanistan, Bahrain, Yemen, and Gaza and, globally, in Sudan, Turkey, Azerbaijan, Thailand, India, Georgia, Bulgaria, Nigeria and even here in Washington, in an attempt to kill the Saudi ambassador and elsewhere in the world, as well as in the cyber-domain, raise the risk of Iranian miscalculation that could spark a disastrous conflict,” he claimed.

Senator Carl Levin, Chairman of the Senate Armed Services Committee said that all options, including military options, need to remain on the table and that preventing Iran from acquiring a nuclear weapon is not only US policy, but that the US is determined to achieve the policy goal.

“Iran is also actively expanding their threat network that has promoted violence across the region in Yemen, Gaza, Sudan, Syria, Iraq and elsewhere. Iran continues to provide financial and material support through the Revolutionary Guard in Lebanese Hezbollah to groups seeking to overthrow or undermine governments or terrorise innocent civilians,” he said.

Responding to questions, Gen Mattis said the collapse of the Assad regime in Syria would be the biggest strategic setback for Iran in 25 years.

“I believe they will arm militias inside the country to try to create a Lebanese Hezbollah-type effect. And they would redouble their efforts vis-a-vis Iraq, Bahrain, Yemen and elsewhere. I think that’s on a strategic plain, what we would see as far as their shift,” he said.

Mattis said Iran obtaining nuclear weapons would be very dangerous for the world.

“It would be dangerous, because it would enable Iran to continue to act like a revolutionary cause, vice a responsible country, and they would sense fewer limitations, and more invulnerability to conducting the kind of attacks that killed Israeli tourists in Bulgaria, provide MANPADS to Yemen, which they were just caught at. I believe we would see more of this irresponsible, reckless behaviour,” he added.