President Erdoğan greets Mohammad & his family

President Recep Tayyip Erdoğan showed the world that Jerusalem was a "red line" for Turkish and Muslims after the United Nations General Assembly adopted a motion Thursday rejecting the U.S. decision to recognize Jerusalem as Israel's capital by a decisive vote of 128 to nine.

Sharing a photo with Mohamed al-Taweel, a 14-year-old Palestinian boy with down syndrome who was detained by Israeli soldiers in the West Bank, the president wrote on his Twitter: "With my brother from al-Quds our message to the world is this: al-Quds (Jerusalem) is our red line."