Taking a huge political gamble, US President Barack Obama on Saturday asked Congress to authorize military action against Syria, in a move which lifted the threat of immediate strikes on President Bashar al-Assad's regime.
Obama said he had decided a chemical weapons attack on a Syrian suburb that killed more than 1,400 people was so heinous that he would respond with a limited US military strike.
But, in a move which could reshape the balance of power between Capitol Hill and the presidency, he said he believed it was important to secure support from Congress to wage war.
The decision represents a leap of faith for a president who has an estranged relationship with Republicans in the divided Congress and he risks suffering the same fate as British Prime Minister David Cameron, who lost his own vote on authorizing military action in parliament.
"I will seek authorization for the use of force from the American people's representatives in Congress," Obama said.
Obama will be relatively confident of winning a vote in the Senate, which is controlled by Democrats and includes a number of Republicans, like Senator John McCain, who have argued for military action against Syria.
But it would be hazardous to predict how the vote will go in the Republican-controlled House of Representatives, which contains conservatives who revile the president and have obstructed his agenda across the board.
House Speaker John Boehner said that the chamber would debate Syria as soon as it comes back into session on September 9, meaning that lawmakers will not be called back early from their summer break.
There had been growing expectations in Washington that military action could even happen as soon as this weekend, but Obama's decision means that will now not happen.
Nevertheless, the president also said that he had decided that the use of force should be the price for what the United States says is the "undeniable" use of chemical weapons by Syria.
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"Our military has positioned assets in the region," Obama said.
"We are prepared to strike whenever we choose."
The US Constitution states that Congress and not the president has the power to declare war.
But in practice, presidents have argued that limited engagements that stop short of full warfare -- as Obama envisages will take place in Syria -- do not require a full authorization.
In asking Congress to weigh in, Obama was sticking to his principles as laid out in his 2008 election campaign, when he argued that the president does not have the power to carry out military action abroad without the consent of Congress.
He may also have had one eye on public opinion, which he admits is war weary amid signs that Americans do not want to enter another Middle Eastern war.
An NBC News poll published on Friday found that half of Americans did not wish to intervene militarily in Syria, where more than 100,000 people have died in a bitter civil war.
Eight in ten of those asked said that the president should get authorization from Congress before launching military action.
Though his decision Saturday will be seen by critics as a climbdown, Obama was adamant that military action was the answer to the chemical attack last week which Washington says killed more than 1,400 people.
"This attack is an assault on human dignity. It also presents a serious danger to our national security. It risks making a mockery of the global prohibition on the use of chemical weapons," Obama said in the White House Rose Garden.
"It endangers our friends and our partners along Syria's borders, including Israel, Jordan, Turkey, Lebanon and Iraq.
"It could lead to escalating use of chemical weapons, or their proliferation to terrorist groups who would do our people harm."