Topic: Richard Clarke - CSMonitor.com

Did a foreign hand guide Boston bombing suspect Tamerlan Tsarnaev?

US investigators are interested in a trip that Tamerlan Tsarnaev, the older brother suspected in the Boston bombing, took to the North Caucasus region of Russia in 2012. They want to know whether he had contact with foreign extremist groups.

Opinion 'Zero Dark Thirty' has the facts wrong – and that's a problem, not just for the Oscars

'Cyber Pearl Harbor': Could future cyberattack really be that devastating?

CIA arrests in Iran? Allegations point to smoldering covert war with US.

'Extensive' porn stash: Three ways US has tried to sully bin Laden's image

Stealth helicopter: Did SEALs have a secret weapon in bin Laden attack?

Osama bin Laden: 7 books that offer insight into the man and his actions

The new cyber arms race

10 ways to prevent cyberconflict

Cyberwar timeline

BlackBerry hacking - who might be doing it?

Walter Rodgers Iraq war: a baffling defense of Bush policy from a former Pentagon insider

Detroit attack: terrorist once again confounds airport security

Al Qaeda No. 2 insults Obama with racial slur in new video