Bin Laden's extremist group had less than a hundred members in September 2001. Today it's a transnational terror organization with 40,000 fighters across the Middle East, Africa and beyond.
Violent radicals are often described as jihadists. A scholar explains what the word means and why those using the word to justify terrorism are often misrepresenting their sources.
After a civil conflict, within five years the majority of modern peace agreements fail. What is causing these negotiated settlements to fall apart?
Many of the men and women who left homes in the West to join ISIS or similar terrorist organizations in Syria and Iraq as fighters or supporters now want to come home. Should they be allowed back?
A schoolgirl who left Bethnal Green to join Islamic State in Syria is now in a refugee camp and wants to return to the UK.
A Taliban perspective on recent peace talks for Afghanistan.
There is a common misconception in the West that leaders of al-Qaida and ISIS are recruiting and brainwashing people into giving up their lives for the Jihad. This is an incorrect model.
An unprecedented onslaught from the US hasn't destroyed the terrorist organization. What is the secret of its resilience?
The latest wave of terrorism aims to kill as many people as possible, as horrifically as possible, with new tools and methods. That makes fighting back more difficult.
When it comes to Islamist extremism and terrorism, change is a constant.
What happens to the Islamic State if it loses the battle for territory in Iraq and Syria? Here's a list of ways it might go down.
The Bastille Day attack in Nice – committed by an individual unknown to French security services – marks the evolution of radicalisation in many ways.
The road to radicalisation can morph from an idea about noble deeds.
Social media were at the heart of the attacks in Paris, serving as tools of communication and also sources of information and emotion.
The British government's position is that this was a legitimate act of self-defence in a war zone. But there are other issues to examine.
Life in the caliphate wasn't exactly as advertised for one group of former fighters.
Western media tropes of black widows, deviant sexuality and unthinking compliance fail to explain why violence crosses the gender divide.
A week of carnage across northern Nigeria proves Boko Haram is alive and well. Can the Nigerian army get its act together?
Attacks in France, Kuwait and Tunisia come against a backdrop of increasing extremist violence across the world.
The Camp Speicher massacre was one of Islamic State's earliest and worst mass killings – but it was nearly buried under a tide of misinterpretation and denial.