For almost three years the Obama administration has been watching a civil war in Syria rage on.
A key American concern was that weapons of mass destruction would be used by the dictator of the country, Bashar al-Assad.
Obama did not like Assad but was not prepared to intervene.
Secretary of State John Kerry, who was also against intervention, had met multiple times with Assad before the civil war began.
But then on Aug. 21, the administration believes, Assad used chemical weapons. Obama said that this action crossed his "red line."
And the administration began to aggressively promote military intervention in Syria against Assad.

