What is behind ISIL's attacks?

After ISIL's deadly attacks on Paris, Beirut and a Russian airliner over Egypt's Sinai Peninsula, has the group changed its strategy?

On this episode of UpFront, Mehdi Hasan asks the former head of counterterrorism for British intelligence and one of the founders of the UN's Counter Terrorism Implementation Task Force (CTITF) about ISIL's tactics and game plan.

We also examine the myth of the Sunni-Shia war, and speak to the leading Muslim scholar Sheikh Hamza Yusuf about the roots of radicalisation.

Headliner: Former head of counterterrorism at MI6 Richard Barrett

Over the past month, ISIL has claimed responsibility for bringing down a Russian airliner over Egypt's Sinai Peninsula, suicide blasts in Beirut and attacks in Paris.

Both Russia and France have responded by intensifying air strikes against ISIL targets in Syria. Across the West, heightened concerns have prompted officials to bolster security measures, with ISIL vowing to strike again.

So, what's behind the group's recent string of attacks? Is ISIL changing its strategy to bring about a confrontation with the West or is it trying to deter further military attacks on its so-called caliphate?

In this week's Headliner, Mehdi Hasan asks Richard Barrett, the former head of counterterrorism at MI6, about ISIL's motivation.

Reality Check: The myth of a Sunni-Shia war

What is driving the current violence and chaos in the Middle East? Many say it's the "age-old" sectarian conflict between Sunnis and Shia, but a look at the facts shows something different.

In this week's Reality Check, Mehdi Hasan highlights the myth of the so-called Sunni-Shia war.

Special: Sheikh Hamza Yusuf

Leading US Muslim scholar Sheikh Hamza Yusuf has been at the forefront of efforts to counter the narrative of ISIL.

As the cofounder of the only Muslim liberal arts college in the US, Yusuf has worked to stop young Muslims in the West from going to fight for ISIL.

In an interview recorded before the recent attacks in Paris, Beirut and Baghdad, Mehdi Hasan asks Yusuf what is behind the allure of the group for some people and why they join it.