I was in New York on the night President Barack Obama announced Navy SEALs had killed Osama bin Laden.

Obama was intensely disliked by Republicans at the time, but partisan rivalry was set aside for a moment of true, unified joy at the death of the world’s most wanted terrorist.

People of all political leanings took to the streets to chant ‘USA! USA!’ as they celebrated the wicked Al Qaeda leader’s grisly demise in a Pakistan shoot-out.

It didn’t matter how you voted, what mattered was that the man who masterminded 9/11 had finally been made to pay for his despicable crimes.

It was a great day for America, and for the world.

America was united in triumph when the mastermind of 9/11 - Osama Bin Laden (top right) was killed under the Obama administration. But yesterday, when the founder and leader of ISIS Abu Bakr al-Baghdadi (top left) President Trump was greeted by booing when he attended a World Series game.

Yesterday was another of those days.

In fact, some argue it was an even greater day.

Abu Bakr al-Baghdadi was the founder and leader of ISIS, a terrorist group that makes even Al Qaeda look like choirboys.

For five years, after declaring Islamic State as a worldwide caliphate, Baghdadi presided over one of the most brutal, evil periods of unconscionable terrorist activity in modern history.

Both administrations released photographs as the presidents and their military leaders watched the moment both terrorist leaders were killed in American strikes

His followers burned victims alive in cages or slowly drowned them. They threw gay people off rooftops, and beheaded others on videos they then broadcast online.

They executed 13 teenage boys in Iraq with machine guns because they were watching a football match on TV.

They shot, suicide-bombed and massacred any rival Shia Muslims they could find in a relentless frenzied attempt to ethnically cleanse them off the face of the planet.

They murdered anyone who tried to leave their caliphate, or those they deemed ‘ineffective in battle’.

His followers burned victims alive in cages - like Jordanian pilot Moaz al-Kasasbeh, above, - or slowly drowned them. They threw gay people off rooftops, and beheaded others on videos they then broadcast online.

They kidnapped thousands of women, especially Kurds or Yazidis, and either sold them as sex slaves or forced them to marry ISIS fighters and be their sex slaves. Many were tortured, or killed themselves to escape the torment.

They trafficked human organs they ripped from living captives and hostages, including children.

They used brainwashed kids as young as six to be front line shields.

As Baghdadi’s terrible tentacles spread ever further around the world, fueled by constant ISIS propaganda on the internet, the scale and ferocity of attacks against civilians worsened.

In January 2015, ISIS terrorists armed with assault rifles stormed the Paris offices of the satirical magazine Charlie Hebdo, killing 12 people.

This is the moment Charlie Hebdo terrorists shot dead an injured policeman during an attack on a satirical magazine - gunning him down at close range as he held his hands up

A few months later, ISIS carried out coordinated attacks in the same city at a football stadium, cafes and the Bataclan concert hall – killing 130 people and wounding 350.

In 2016, ISIS claimed responsibility when a man in a large truck drove through a crowd in Nice, France on Bastille Day, murdering 84 and injuring 330.

A year later, an ISIS-inspired suicide bomber attacked an Ariana Grande pop concert in Manchester, England, killing 22 predominantly young girls and wounding another 59.

French fire brigade members aid an injured individual near the Bataclan concert hall following fatal shootings in Paris, France, November 13, 2015

All of this was conducted on Baghdadi’s watch.

He was the boss, the driving force, the brains behind the barbarism.

So yesterday was a truly great day for America and the world.

It was the day this monster was no longer alive to continue his disgusting reign of unimaginable horror and depravity.

It should have been a day that once again unified all Americans, even in these hyper-partisan times.

Yet last night, I turned on the World Series baseball game in Washington D.C. to see the crowd loudly booing their president.

It was a staggering thing to observe: thousands of Americans gleefully jeering and mocking President Trump, the man who had just successfully ordered Baghdadi’s death.

The shock I felt had nothing to do with a group of D.C. people booing Trump; America’s capital city is the most intensely Trump-loathing place in the country (90% voted for Hillary in 2016) and for many of its extreme liberal inhabitants, booing him is a 24/7 obsession.

Shockingly, thousands of Americans gleefully jeered and mocked President Trump, the man who had just successfully ordered Baghdadi’s death as he attended the World series game in Washington yesterday (seen arriving above)

No, the shock I felt was to do with the timing of this booing.

Frankly, whatever you think of Trump, it beggars belief to me that any American would choose yesterday to abuse their president.

There are many legitimate reasons to dislike him.

He’s comfortably the most divisive and polarizing president in modern United States history, a man whose inflammatory rhetoric has done much, though by no means all, to fuel the toxicity of current American political discourse.

And his possibly impeachable conduct over the Ukraine ‘quid pro quo’ scandal, and his outrageous decision to throw U.S. allies the Kurds under the bus in Syria, have all made him even more unpopular at the moment.

Even the way he announced the news of Baghdadi’s death was typically Trumpian, and to many of his critics, ‘unpresidential’.

From his gloating bombast and security-threatening over-sharing about the raid, to his false claim that only he had previously warned of the dangers posed of bin Laden, and his shockingly inappropriate book plug, it was a needlessly self-aggrandising performance when all Trump had to say was: ‘I ordered a successful mission to kill the world’s most dangerous terrorist’.

That stunning fact alone is something that can win elections.

He didn’t need all the extra off-script blather, though personally, I liked hearing the gory details of Baghdadi’s final moments.

Nothing begets a man more than the manner of his death, and now the whole world knows Baghdadi was a sniveling little coward who dragged three of his own poor children to their deaths in a desperate attempt to save himself.

So President Trump never helps himself, and there are many perfectly legitimate criticisms to be leveled at him.

BUT, and I think it’s a big ‘BUT’, last night was not the time to do it.

Last night was a time for America to put aside its insanely vicious partisan feuding and just celebrate the demise of the worst person on Planet Earth.

That’s not, as some of his enemies would have you believe, Donald Trump.

It was Abu Bakr al-Baghdadi.

His death is a massive boost for American in its war on terror.

It cuts the head off ISIS at the precise moment its entire existence is teetering on the brink of collapse.

It’s no exaggeration to say this might hasten the end of ISIS altogether, though we can certainly expect some form of reprisal attacks in the wake of Baghdadi’s death as the few remaining ISIS fighters desperately try to rally support.

So regardless of your view of Trump, and I’ve been as critical of him in recent weeks as anyone, this was a moment to praise him for taking the bold, courageous decision to order a dangerous mission that successfully took out the leader of ISIS.

Of course, most of the praise should go to the heroic special forces operatives that carried out the mission, and the much-maligned – not least by Trump - U.S. intelligence agencies who helped track Baghdadi down.

But Trump himself still deserves great credit for ordering the operation. If it had failed, Baghdadi had escaped and US forces had been killed, it would have been a disaster for America and for him.

I wouldn’t say, as Trump predictably did, that it was a bigger moment than bin Laden’s death, given how uniquely emotive and vengeful Americans understandably felt after 9/11, but it was certainly as significant.

So for Americans to use this moment to boo their president, and chant ‘Lock him up!’ seems crass, wrong and unpatriotic.

Yes, I know Trump’s encourages his own supporters to do this to Hillary Clinton at all his base rallies.

But just because he’s wrong to do that, which he is, it doesn’t make it right to do it to him on such an important day.

In fact, it makes it unpatriotic and shameful.

When bin Laden was killed, the images of Americans coming together in joy went round the world and were a powerful symbol of unity.

Today, the only images people will see are of Americans booing their president for helping to kill the leader of ISIS.

Yes, it was a bad look for Trump.

But it’s a far worse look for America.