A profile of the terrorist organization based in the southern Philippines.

The "July War" showcased Hizballah's evolution into an adaptive, skillful, cohesive fighting force capable of registering some measure of success on the battlefield against a much larger and better equipped enemy, says this report from the Washington Institute.

New Yorker Staff Writer Lawrence Wright shares his insights into al-Qaeda, the ideas and individuals behind the terrorist organization, and the Western intelligence failures leading up to 9/11.

As the cease-fire between the Tamil Tiger terrorist group and the Sri Lankan government crumbles, the South Asian nation is on the verge of being engulfed in another round of its decades-old civil war.

Al-Qaeda and Hezbollah are supposedly rival groups on opposite sides of sectarian lines. Yet recent statements from senior al-Qaeda leadership suggest a common enemy may be drawing them together, and experts believe such a liaison could pose grave new dangers for the United States.

There are concerns the war in Lebanon may have pushed two of the world's most prominent terrorist groups closer together. Though Al-Qaeda and Hezbollah have shared interests in opposing the United States and Israel, their sectarian differences have been aggravated by the conflict in Iraq.

CFR Senior Fellow Steven Simon says the plot uncovered by British authorities to simultaneously down several aircraft over the Atlantic Ocean bears all the hallmarks of al-Qaeda and suggests the group is still a viable threat.

A profile of Abu Nidal, a terrorist organization opposed to the state of Israel.

Since 9/11, much of al-Qaeda's operational capacity has been dismantled but experts say the group's strength now lies in its ability to inspire others to carry out terrorist attacks.

A profile of a militant Islamist Kurdish separatist movement seeking to transform Iraq into an Islamic state.

A profile of the Japanese religious cult that carried out the 1995 subway sarin attack.

A profile of Greek leftist terrorist groups.