Donald J. Trump is home from his whirlwind weekend trip to commemorate the 100th anniversary of the First World War’s end. Even by The Donald’s formidable china-breaking standards, this was a doozy which will be discussed with opprobrium by the Transatlantic smart set for some time.

President Trump seemed to go out of his way to upset his French counterpart and host Emmanuel Macron, who’s hit a political rough patch and needed some brotherly love. That bromance is dead and buried, however, and Trump fired off a mocking tweet at Macron as he boarded Air Force One for Paris that denounced the French president’s backing of a European army as ‘very insulting.’

This rattled the Élysée Palace yet, while Trump’s use of Twitter to conduct diplomacy was its usual silliness, the point stands. Washington has always opposed any EU army, on the sensible grounds that it will weaken NATO. Since hardly any European NATO members spend the ‘required’ two percent of GDP on defense, the notion that there’s enough cash on hand to have a viable European army while keeping the Atlantic Alliance afloat is laughable. Not to mention there are only two major EU countries that take defense seriously, fiscally and otherwise – Britain and Poland – and the former is on its way out of the Union while Brussels is doing its best to evict the latter.

Therefore, the notion of a European army is risible, though a tweet is not the best way to point that out. Macron got his revenge on home turf, making the Armistice Day commemoration a showcase of multilateralism and Western unity, which Trump seems to loathe. Before the world, Macron denounced nationalism, a recent subject of Trumpian praise, pointedly stating, ‘Patriotism is the exact opposite of nationalism,’ adding acidly, ‘there are old demons which are coming back to the surface. They are ready to wreak chaos and death.’

Taking Trump to task over his hailing of American nationalism is an easy target, and Macron received unctuous praise from Western elites who hate Trump already. They seem not to be aware that iconic Republican President Teddy Roosevelt hailed ‘New Nationalism’ in America over a century ago. Moreover, it’s not clear what Trump exactly means by American nationalism today – concise definitions not being one of The Donald’s strongpoints – since European-style Blut und Boden nationalism has never made sense in multiethnic and multicultural America.

Neither is obvious that all Europe agrees with Macron here. The French president made the weekend an explicitly Western European event. Throughout, window-dressing aside, the Armistice Day commemoration was about France and Germany. As Macron stated while holding the hand of Angela Merkel, Germany’s chancellor, ‘Europe has been at peace for 73 years.’ This would be news in Southeastern Europe, including Sarajevo which, Macron seems to have forgotten, is where the First World War started.

What got the lion’s share of attention was Trump’s punting on his signature event, a Saturday visit to the American cemetery at Aisne-Marne, near the famous Belleau Wood battleground. The event was tersely canceled. Staffers proffered strange excuses about rain grounding the presidential helicopter. No other dignitaries were similarly shut-in. Canadian Prime Minister Justin Trudeau had no trouble getting to his country’s cemetery at Vimy, twice as far from Paris as Trump’s destination.

Images of Trump watching TV while scarfing down cheeseburgers, safe from the rain, proliferated widely. Mocking on social media came hot and heavy, with the prize going to Conservative MP Nicholas Soames, Winston Churchill’s grandson, who tweeted: ‘They died with their face to the foe and that pathetic inadequate @realDonaldTrump couldn’t even defy the weather to pay his respects to The Fallen #hesnotfittorepresenthisgreatcountry

The damage was done and was not repaired by Trump’s consolation speech the following day at the American cemetery at Suresnes, closer to Paris. That speech was so anodyne as to be barely recognizable as Trumpian oratory. The president’s non-appearance on Saturday defined his trip for the world.

That’s unfortunate since a golden opportunity was missed for Trump to be himself at Aisne-Marne. As many have noted, the president campaigned as a skeptic about rampant American interventionism abroad yet has governed as a rather conventional Republican. While Trump deserves praise for not starting any more needless wars of choice – a low bar not cleared by his predecessor – neither has he ended America’s underperforming forever war in Afghanistan, now in its 17th year. Saber-rattling by cabinet hawks against Iran indicates that neoconservative adventurism is neither dead nor buried and is nested in the White House.

President Trump ought to have used his Saturday platform to tell Europeans what an awful idea American intervention in the First World War really was. It did nothing good for America, and plenty bad for Europe too. After the required boilerplate about honoring the dead, point out that Woodrow Wilson – a virulent racist who trampled on civil liberties at home – knew nothing about Europe but wanted to remake it. Wilson, an Ivy League professor and progressive from central casting, knew better.

Remind that American intervention in the war was led by strange religious fervor and do-gooder beliefs that America’s moral superiority meant it could remake whole regions by force of ideas. Point out how eerily similar all this was to the ramp-up to George W. Bush’s madcap invasion of Iraq in 2003 (Europeans will like that), hint that there was nothing ‘conservative’ about any of this strategic delusion.

Claim credit for victory in 1918: American entry in the war broke the stalemate and ensured Allied victory. As Winston Churchill said concisely, ‘the moral consequence of the United States joining the Allies was indeed the deciding cause in the conflict,’ adding that without American intervention the war ‘would have ended in a peace by negotiation.’ Yes, that would have meant a Europe dominated by Germany, but you have that today.

Moreover, Wilhelmine Germany, for all its faults, bore no resemblance to Hitler’s Third Reich. With a compromise peace in the West, the Germans would have promptly crushed the Bolshevik menace rising in the East like a bug. Then, no Fascism, no National Socialism, no Holocaust. Not to mention that Wilson’s strange ideas about Eastern Europe would have never seen the light of day and the chaos in the Balkans and beyond birthed by the war’s end, still quite alive today, would have been stillborn.

Conclude by stating that Wilsonianism was a terrible idea that made the world a worse place due to New World naïveté. Add that America, finally, has learned its lesson. While the United States will honor its commitments and stand by its longtime allies, it will not seek to remake the world in its own image by force. Closeout with John Quincy Adams’ words that our Republic ‘goes not abroad, in search of monsters to destroy. She is the well-wisher to the freedom and independence of all. She is the champion and vindicator only of her own.’

That speech would have demonstrated that President Trump is sincere about remaking American foreign policy for the new century, learning the lessons of the last one. Too bad he didn’t brave the rain on Saturday.