U.S. President Barack Obama this week sent a stern warning to Syrian President Bashar al-Assad not to unleash chemical weapons on his own people. The president's words came amid fears that Syrian forces were mixing chemical weapons -- apparently sarin gas -- to use against opposition rebels in that country's 20-month-old civil war. You can read more about the American reaction to those reports here.
Obama left unsaid the idea that the U.S. might use military force against Syria if Assad resorts to chemical weapons. Nevertheless, he said chemical weapons usage in the civil war was unacceptable, and Assad must refrain from such action as "the world is watching."