The following soundbite is from President Barack Obama's address to the nation Tuesday evening, explaining his decision to prepare for possible military strikes on Syria.
President Obama said it is clear that the Syrian government was responsible for the use of chemical weapons.
"In the days leading up to August 21st, we know that (Syrian President Bashar al-Assad) Assad's chemical weapons personnel prepared for an attack near an area where they mix sarin gas. They distributed gas masks to their troops. Then, they fired rockets from a regime-controlled area into 11 neighborhoods that the regime has been trying to wipe clear of opposition forces. Shortly after those rockets landed, the gas spread and hospitals filled with the dying and the wounded. We know senior figures in Assad's military machine reviewed the results of the attack and the regime increased their shelling of the same neighborhoods in the days that followed. We've also studied samples of blood and hair from people at the site that tested positive for sarin."