The United States and the United Kingdom have stopped all non-lethal assistance to rebel groups in northern Syria after al Qaeda-linked factions seized the headquarters and warehouses belonging to the opposition's Supreme Military Council.

Fighters from a union of six Islamist factions calling themselves “The Islamic Front” took control of the Free Syrian Army bases at the Bab al-Hawa crossing on Syria's northwestern border with Turkey late on Friday.  Turkey responded by closing that border crossing.

Non-lethal assistance includes radios and communications equipment, body armor, night vision goggles, and medical supplies to assist the rebels fighting President Bashar Assad.

It’s not clear why the Islamists seized the larger federation’s premises, and what material goods they’re getting out of it.  But infighting among rebels has significantly weakened their efforts to bring down Assad.

Earlier this year, the United States doubled its non-lethal aid to opposition forces in Syria, and there was even pressure on the White House to support the rebels with air strikes.  That plan was scrapped because of America’s war fatigue, and a series of embarrassing-to-horrifying episodes involving the rebels, including civilian massacres and one rebel who posted a video to the internet showing him eating a government soldier’s heart.