The legacy of the 2003 US-led Iraq war hangs heavy over the prospect of punitive US military strikes against Syria, both at home and abroad, dpa reported.
In making the case for action against Syrian President Bashar al-Assad's regime for its alleged use of chemical weapons, US President Barack Obama has gone to great lengths to differentiate between Iraq and Syria.
In 2002, the US Congress overwhelmingly backed then-president George W Bush's call for war on Iraq, swept along by the administration's "proof" that Saddam Hussein had a large store of weapons of mass destruction and by the atmosphere of fear after the 2001 terrorist attacks. Bush's declared goal was regime change.
Once again, a US president is asking Congress to authorize an act of war over chemical weapons, but Obama has insisted that Syria is different.
"It does not involve boots on the ground. This is not Iraq," he said.
For one, the goal is not regime change, nor even protection of civilians, 100,000 of whom have died in close to three years of war.
Ever mindful of the war he opposed as a presidential candidate, Obama has said Washington's likely response in Syria will be restricted to limited missile strikes over a 30- to 60-day period - "a shot across the bow" designed to degrade Damascus' chemical weapons capabilities, rather than an invasion seeking regime change.
Despite the more cautious approach, analysts warn that Washington is entering Syria without well-defined goals or parallel political and diplomatic tracks to ensure a swift exit - the lack of which mired the United States in Iraq 10 years ago.
"The case has been made that Syria is not Iraq, but has the US really learned from Iraq before entering Syria?" said Salman Shaikh, the head of the Doha-based Brookings Center.
"Going in without a clear and robust mandate as well as a political strategy in hand, I am afraid that the United States may be taking on much more than Obama has bargained for."
In France, the only other nation that is openly considering support for a military strike against Syria, the Iraq analogies have been mainly about the rush to war without waiting for proof from UN investigators.
"The Middle East backdrop, the accusations about weapons of mass destruction held by an authoritarian regime, an American administration claiming it has proof and saying it is ready to act without the support of the United Nations - there is a sense of deja vu about it all," the French edition of the Huffington Post wrote last week.
Prime Minister Jean-Marc Ayrault told parliament that France still wanted to see al-Assad leave power, but Defence Minister Jean-Yves Le Drian assured that toppling al-Assad would not be the aim of missile strikes.
Then, on Friday, French President Francois Hollande said he would wait for the UN report before taking a final decision on action against Syria, adding that this would help mobilize more support for a coalition.
Obama is also largely reluctant to allow a flow of arms and financial support to rebel forces out of fears that weapons will fall into the hands of al-Qaeda-affiliated militants, who destabilized neighbouring Iraq and led attacks against US forces.
Aside from limited training for rebel Free Syrian Army officers, the US has stopped short of providing full military and financial backing to the opposition, leaving it without a viable ally on the ground.
"Now not only has this lack of support tipped the conflict to the point that the West has to intervene, but now there is no strong opposition force on the ground to step in should the regime fall," said Nadim Shehadi of the London-based Chatham House think tank.
This week's front page photos in The New York Times of rebels assassinating Syrian soldiers, stripped above the waist and crouching on the ground, has horrified many in Congress over US plans to arm the rebels.
The al-Qaeda legacy in Iraq and Afghanistan, where terrorists gained strength in the chaos of war, is also on the minds of critics, given increasing evidence of the involvement of Islamist militants in the Syrian war.
"This is not our fight - we're going to pick sides between Iran and (al-Assad) on the one side and al-Qaeda on the other? It makes absolutely no sense," Representative John Culberson was quoted as saying in the National Journal.
Yet, despite credible evidence that toxic gas was used in the August 21 attack outside Damascus in which Washington says more than 1,400 people were killed, observers say the Iraq parallels have prevented Washington from pushing for a UN mandate or forming a wider international coalition needed to render the military action in Syria a success.
"Unlike Iraq, we have clear evidence that chemical weapons have been used against civilians multiple times, yet we still have to see a single UN resolution or mandate," Shaikh said.
He continued: "This has left us to a weak response to a regime that has proven that it has and will likely continue to use chemical weapons against its own people, even after the attacks."