US intelligence officials still know relatively little about the workings of Islamic State militants. James Foley may have been traded by insurgent groups before ending up in IS hands, which complicates the intelligence picture.
President Obama said he hoped that the role of the National Guard would be limited, and suggested that local police departments reexamine their use of heavy military equipment when confronting protesters.
Obama sought to reassure Americans that the attacks in northern Iraq would not lead to another US war. But the air strikes will have limited impact against the dispersed militants without ground-based personnel, some analysts say.
Retired Gen. Stanley McChrystal, forced to step down after published remarks critical of the president, endorsed former Marine Seth Moulton for a US House race – prompting speculation that he's open to run himself.
Pentagon officials insist that the death of the highest-ranking US officer in America’s post-9/11 war effort will not change US strategy in Afghanistan. Mission No. 1 is to train Afghan counterparts ahead of US combat forces leaving.
Former CIA Director Woolsey tells Congress of a doomsday scenario in which a nuclear-blast-triggered electromagnetic pulse takes down the US power grid, leading to starvation and death. Some experts decry 'hysteria' over EMPs.
The office of the Special Inspector General for Afghanistan Reconstruction, in its latest report on the $104 billion project, takes the Pentagon and Afghanistan government to task for a broad range of questionable policies.
Pentagon analysts are grappling with what this growing unrest in the Middle East means for US national security. Here are the top three ways the advance of the insurgent group the Islamic State in Iraq and violence in Gaza could endanger US national security.
Hamas this week showed it has drones at its disposal, forcing Israel to use a Patriot missile to shoot down one that had entered its airspace. Its drones are low-tech, but they have the attention of US defense analysts.