Mary Louise Kelly

North Korea apparently attempted another ballistic missile launch last week. The launch failed, but U.S. intelligence officials warn the country is learning from these mistakes.

News that the FBI arrested a National Security Agency contractor for stealing classified material is prompting questions about the agency's internal security after the Edward Snowden leaks in 2013.

The FBI arrested an NSA contractor. Harold Thomas Martin III is in custody, charged with stealing classified materials. The NSA has worried about another inside job since Edward Snowden's 2013 leaks.

Might the recent collapse of U.S.-Russia cooperation on Syria open the door to a possible escalation in cyberwar? Both sides now have more to gain — and lose.

When news broke last month the National Security Agency might have been hacked, suspicion fell on Russia. Now some analysts think an NSA insider might have been involved, wittingly or not.

Edward Snowden is having a big week, as the subject of both a laudatory new Oliver Stone biopic and a scathing report from the House Intelligence Committee. We examine the competing narratives.

You can probably guess what a former deputy director of the National Security Agency thinks of the new biopic on Edward Snowden.

Donald Trump says that if Iran harasses U.S. ships in the Persian Gulf, "they will be shot out of the water." Iranian and U.S. Navy vessels have long played cat-and-mouse in the Gulf.

After the Sept. 11 attacks, Congress authorized the president to act against those responsible. Presidents Bush and Obama have cited that measure ever since in pursuit of multiple groups.

Opponents of Russian President Vladimir Putin and former colleagues who have fallen from favor seem to be dying at an unusual rate. Russia-watchers believe the deaths are not random.

Should the U.S. retaliate for cyberattacks? Options range from sanctions to indictments to a counterattack to nothing. Lawmakers and security experts say there are pros and cons to each approach.

Software code associated with the kind of cyber-surveillance conducted by the National Security Agency has appeared online. This is raising questions about whether the NSA has been hacked. It would be the latest act in this summer's cyber-drama involving compromises to the Democratic National Committee, U.S. leaders and others.

A U.S. nuclear engineer is accused of spying for China. Chinese economic espionage costs the U.S. billions each year. The case raises questions about whether Chinese-Americans are unfairly targeted.

Nick Rasmussen, director of the National Counterterrorism Center, says progress against the Islamic State may be slow to affect the terror attacks plaguing the West.

For generations, Roslyakovo was a secret city with restricted access, even for Russians. The shipbuilding center was a place to work on military technology, and also a perfect place to hide things.

Cybersecurity experts say some evidence points to Russia in a series of hacks on the Democratic Party. Russian officials and Donald Trump both weighed in on the recent hacks as well.

Donald Trump on Wednesday called for Russia to hack Hillary Clinton's email and recover messages from her tenure as secretary of state.

Journalists, dissidents, human rights workers all tell stories of being followed and harassed by Russia's security services. They range from the comical to the frightening.

What evidence ties Russia's intelligence services to the theft and release of the internal emails of Democratic Party officials? And how would the public release those messages serve Moscow?

The recent series of major terror attacks — from Orlando to Istanbul to Nice — have exposed some uncomfortable truths about the limits of counterterrorism.