The hijackers’ travel patterns before the attacks help reveal the terrorists’ organizational structure.
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The U.S. killing of the al-Qaeda leader in Afghanistan was not justified in self-defense or under the international law of war or international human rights law. It looks more like an extrajudicial execution, or revenge murder, for past acts of terrorism.
In the culmination of a manhunt that lasted almost 21 years, the U.S. government appears to have located and killed Ayman al-Zawahiri. Here are the legal questions the Biden administration likely worked through before the strike.
Bin Laden's successor steered the organization through a tumultuous decade and left it stagnated, but the next leader will have new opportunities for growth.
What does it mean when individuals and groups are included in U.N. terrorism reports but don't make the cut for sanctions?
The United States should be exploring new approaches for attaining its counterterrorism goals.
The threat landscape will require careful prioritization.
Counterterrorism experts need to get ahead of the curve of terrorist innovation with new, commercially-available products.
Foreign fighters remain a powerful jihadist force worth understanding.