President Barack Obama made jokes at Donald Trump's expense around Trump's claims on Obama's birth certificate.
For the first time in Donald Trump's controversial presidency, the general consensus is that the former reality star has put Barack Obama in the shade.
The 70-year-old's missile attack on Syria came after his predecessor claimed he had resolved the problem of President Bashar al-Assad harbouring chemical weapons in a murky deal brokered by Russia, according to news.com.au.
Obama proudly named it one of his greatest successes in his memoirs, but he may have to backtrack on that stance after the sickening gas attack that killed 80 civilians.
It is this attack, believed to have been carried out by the Syrian president against his own people, that triggered Trump's punitive response, in which 59 missiles were launched at the airfield from which the chemical attack is believed to have originated.
Could Obama have done the same earlier and prevented those deaths? Is this his greatest failure?
Obama struggled with the Syria problem throughout his tenure, but it was a chemical attack that killed 1400 civilians in 2013 that crossed what the then-US President had called his "red line".
At this point, he too considered a military strike, but his fears of another unwinnable war in the Middle East after Iraq meant he was more reluctant than Trump.
Unlike his successor, he took the question to Congress, who voted against an attack.
That's when Vladimir Putin stepped in, offering to broker a deal in which Syria would join the Chemical Weapons Convention and Assad would give up his chemical weapons arsenal.
In a dramatic role reversal, Obama put his faith in Russia where Trump defied Putin's wishes.
By August 2014, the Obama administration was celebrating its success in, as the President put it, "eliminating Syria's declared chemical weapons stockpile."
Secretary of State John Kerry hailed "a deal where we got 100 per cent of the chemical weapons out."
And Obama's national security adviser Susan Rice boasted in January that the administration had got the Syrian government to "voluntarily and verifiably" give up its weapons "in a way that the use of force would never have accomplished."
But the deadly events of last week showed this to be a fatally premature assumption.
Abdul-Hamid Alyousef, 29, cries as he holds his twin babies who were killed during a suspected chemical weapons attack, in Khan Sheikhoun, in the northern province of Idlib, Syria. Photo/AP
Clues to the fatal mistake
Looking back, there appear to have been many signs Assad might not have rid himself of all chemical weapons.
Obama's advisers would at times refer only to eliminating "known" or "declared" stockpiles.
In February 2016, national intelligence director James Clapper Jr told Congress directly: "We assess that Syria has not declared all the elements of its chemical weapons program."
Elliott Abrams, former deputy national security adviser to George W. Bush, told the New York Times: "The defence was that he got all the CW [chemical weapons] out, and now that defence is shown to be plain false."
Tom Malinowski, an assistant secretary of state for human rights for Obama, wrote in The Atlantic this weekend that he had learnt "deterrence is more effective than disarmament" when dealing with mass murder.
Obama supporters maintain that removing 1300 tons of chemical weapons from Syria was a win that may have helped keep dangerous assets out of the hands of terrorists.
But former deputy secretary of state Antony Blinken told the NYT: "We always knew we had not gotten everything, that the Syrians had not been fully forthcoming in their declaration."
The Lowy Institute's Rodger Shanahan told news.com.au it "always easy in hindsight" to say someone should have done something different. "It was a deal [Obama] believed would outweigh the benefit he could achieve with a strike.
"My personal view is I think he could have done both a limited strike and a deal. He could have got the same deal by being a bit firmer, and swapped limited military action for a chemical non-proliferation deal. He could have threatened more."
Why Trump's strike is not the final answer
Trump has been praised from all kinds of quarters following his strike against Syria and its use of chemical weapons.
Left-wing US commentators and Democrats say the President did the right thing, although conservative supporters were less enthusiastic.
"It's given him a short-term boost but that's all," said Dr Shanahan.
"He was presented with a problem that was pretty straightforward and he made the deicsion quickly ... he's shown Syrian actors that there are limits."
We have learnt the hard way that the Syria problem will not easily go away, and the missile strike may not signal an end to the deaths.
The war in Syria has claimed around 400,000 lives and left 6.5 million people displaced in what has been declared the worst conflict of the 21st Century.
Syria descended into full-scale civil war in 2012, as forces loyal to Assad and rebels opposed to his rule battle each other and jihadists.
After Obama's removal of chemical agent sarin, Assad's forces began using makeshift chlorine bombs, which contained a chemical not banned under the agreement.
There is no reason the Syrian regime will not continue using alternative weapons to commit mass genocide following Trump's strike.
Russia has condemned Trump's attack as "illegal" and warned the US is "one step away" from war, but Dr Shanahan believes Putin is more likely to think "the Syrians had it coming" and be angry at the loss of a geostrategic upper hand.
"If the Syrian government used chemical weapons, Russia would not be happy." he said.
"They had a tactical advantage.
"Trump hasn't had any retaliation. You've got to distinguish between public and private. If there's no action following the rhetoric, it's just rhetoric."
