Obama takes the biggest gamble of his presidency
The indecision and paralysis are over.
America will now take the fight to the Islamic State, irrespective of geography and borders.There will be no sanctuary for the extremists.
This President - a leader who thought his legacy would be ending two conflicts - has now plunged the United States into the maelstrom of two civil wars.
Of course he didn't put it like that. President Obama portrayed it as a counter-terrorism intervention, and one that wouldn't involve ground troops. He compared it to Somalia and Yemen.
But he wasn't being exactly candid. America will be spending billions of dollars, and deploying trainers, advisers and CIA agents, to both Syria and Iraq. This is an operation that will outlast his Presidency.
The cautious, careful leader who was elected as the antithesis of George W Bush has just taken the greatest gamble of his Presidency.
It's a gamble because he has designed a military campaign that he can't control.
The President is relying on moderate Syrian opposition forces filling the vacuum. And by most accounts they are mirage. There are no moderates left.
And he is reliant on countries like Saudi Arabia, Qatar, the UAE, Jordan and Turkey - the key regional actors - stepping up and helping the US. Don't hold your breath. They all have their own agendas.
In the short term, the President succeeded last night. He persuaded Americans that the Islamic State is a serious global threat that must be confronted.
But the White House is now hostage to a set of circumstances that could destroy Obama's second term.
Many in the Middle East will conclude that America has taken sides in the sectarian war. They will say the US is now backing Shiites over Sunnis. Critics will point out that Washington is strengthening the hated Assad regime by attacking the Islamist enemies of Damascus.
President Obama is expected to wait a few weeks to refine the intelligence before he approves the first bombing raids into Syria.
But he has made his promise to the American people: The Islamic State will be degraded and destroyed.
Now in the autumn of his Presidency he is taking a divided, ambivalent and weary country back to war in a region few Americans understand.
Read more: Obama: US will lead coalition to 'destroy Islamic State'