Islamic State crisis: Obama threatens action in Syria
President Obama's anti-IS strategy
A systematic campaign of airstrikes against IS targets "wherever they are", including in Syria
Increased support for allied ground forces fighting against IS - but not President Assad of Syria
More counter-terrorism efforts to cut off the group's funding and help stem the flow of fighters into the Middle East
Continuing humanitarian assistance to civilians affected by the IS advance
Analysis: Jon Sopel, BBC North America editor, Washington
For the first time, Islamic State targets on the ground in Syria will be in the crosshairs of American pilots. The president told the American people: "I have made it clear that we will hunt down terrorists who threaten our country, wherever they are." But he was equally emphatic that the combat on the ground would happen without US troops. Instead the US will ramp up its military assistance to the Syrian opposition.
But the president was also at pains to express what this wasn't. "We will not get dragged into another ground war," he insisted. He said that America would lead a broad coalition to roll back this terrorist threat and would not be acting alone. There were two cautionary notes - the first on timescale and also that this would not be risk-free to American servicemen and women. Action is going to start: who knows when it will be mission accomplished.