Eric Schmitt

Russian attack submarines are prowling the coastlines of Scandinavia and Scotland, the Mediterranean Sea and the North Atlantic in what Western military officials say is a significantly increased presence aimed at contesting U.S. and NATO undersea dominance.

An Islamic State detainee currently in U.S. custody at a temporary detention facility in Erbil, Iraq, is a specialist in chemical weapons whom U.S. military officials are questioning about plans to use the banned substances in Iraq and Syria.

Russia has asked the Obama administration for permission to fly surveillance planes equipped with high-powered digital cameras over the United States, fueling a long-simmering debate among Pentagon and intelligence officials over the Open Skies Treaty.

U.S. warplanes struck an Islamic State camp in Libya early Friday, targeting a senior Tunisian operative linked to two major terrorist attacks in Tunisia last year.

A crisis over the seizing of two U.S. patrol boats in the Persian Gulf was averted Wednesday when Iran returned the craft and released their crews as Pentagon officials struggled to explain how the boats had ended up near a major Iranian naval base.

When a lonely Virginia teenager named Ali Amin got curious about the Islamic State last year and went online to learn more, he found a virtual community awaiting.

The day before Thanksgiving, President Barack Obama reassured Americans there was “no specific and credible intelligence indicating a plot on the homeland.” Seven days later came the deadliest terrorist attack in America since Sept. 11, 2001.

Defying Western efforts to confront the Islamic State on the battlefield, the group has evolved in its reach and organizational ability, with increasingly dangerous hubs outside Iraq and Syria and strategies that call for using spectacular acts of violence against civilians.

As the United States prepares to intensify airstrikes against the Islamic State in Syria, the Arab allies who with great fanfare sent warplanes on the initial missions there a year ago have largely vanished from the campaign.

Russian submarines and spy ships are aggressively operating near the vital undersea cables that carry almost all global Internet communications, raising concerns that they may plan to attack those lines in times of tension or conflict.

The raid was the first time U.S. soldiers had been confirmed to be directly accompanying local forces in Iraq onto the battlefield against the Islamic State since President Barack Obama sent troops back to the country last year.

The Obama administration acknowledged the failure of its $500 million campaign to train thousands of fighters and announced that it will instead use the money to provide ammunition and some weapons for groups already engaged in the battle.

The Obama administration has ended the Pentagon’s $500 million program to train and equip Syrian rebels, administration officials said Friday, in an acknowledgment that the beleaguered program had failed to produce any kind of ground combat forces capable of taking on the Islamic State in Syria.

One of the two brothers suspected of killing 12 people at a satirical newspaper in Paris traveled to Yemen in 2011 and received terrorist training from al-Qaida’s affiliate there before returning to France, a senior U.S. official said Thursday.