The YouTube-posted video of Marines urinating on slain Taliban fighters was a factor in the insider attack that killed four French troops and rattled the unity of coalition forces in Afghanistan, Marine Gen. John Allen said Monday.

The U.S. has made clear to Iraq that it shouldn't allow Iran to use its airspace to fly weapons and fighters to Syria, U.S. Secretary of State John Kerry says. Some U.S. lawmakers are calling for President Barack Obama to do wade deeper into the Syrian conflict.

A Marine killed a male and female colleague in a shooting at a base in northern Virginia before killing himself. He had barricaded himself in the barracks at the base's officer candidate school during a standoff with authorities, officials said.