Obama war powers revision puts strike decision in Congress's lap President Barack Obama has decided the crisis in Syria, which he calls "the worst chemical weapons attack of the 21st century," requires delay. In asking for Congress to approve bombing Syria, Mr Obama has reset the notion of presidential authority about war powers that has increasingly resided with the executive branch since the end of World War II. It is also one of the greatest gambles of his presidency in that he is seeking approval from a Congress that, at least in the Republican-controlled House of Representatives, has fought him at every turn. Mr Obama's conviction on Saturday and the moral outrage of Secretary of State John Kerry a day before suggest they believe, having seen all the evidence and not just the declassified portion seen by lawmakers, that they will win the debate once Congress is fully informed. White House officials say he is shifting the burden to Congress. The authority of the Senate and the House in matters of war was debated intensely before the second conflict in Iraq. At that time, the then senators Vice-President Joe Biden, Mr Kerry and Defence Secretary Chuck Hagel all said President George W. Bush had overstepped his authority. Mr Obama's criticism helped propel him to the Senate and, eventually, the White House. In an interview with the Boston Globe in 2007, Mr Obama was asked in what circumstances, if any, a president would have constitutional authority to bomb Iran without seeking a use-of-force authorisation from Congress. "The president does not have power under the constitution to unilaterally authorise a military attack in a situation that does not involve stopping an actual or imminent threat to the nation," Mr Obama said. His decision marks a rare moment in the past half century when a president unilaterally decides to give some power back. "It's quite uncertain what a military strike is going to produce," said presidential historian Robert Dallek. He really shouldn't go it alone. It's wise to bring Congress into it. It gets him much more of a broad consensus. Lee Hamilton, a Democrat and former chairman of the House foreign affairs and intelligence committees, said: "You will have the support of the Congress, which shares the burden. It will help him internationally, which will see the country is united.