Best Of: ISIS — From the Ground to Cyber Space

There are two schools of thought about the nature of the threat posed by the Islamic State in Iraq and Syria (ISIS). Some experts say the group is nearly vanquished as it struggles to hold on to Mosul, Iraq, and prepares for the inevitable fight for its capital in Raqqa, Syria. Other analysts see ISIS as invincible, destined to wreak havoc in the Middle East for the next decade and beyond.

In some ways, both of these perceptions are true, which is why ISIS is such a unique adversary and terrorism such a difficult tactic to combat.