President Macron’s decision to fly to Rome this week to meet with Italy’s new prime minister, Giorgia Meloni, will likely do little to shore up his flagging approval ratings. The itinerant French president’s rendezvous with Ms. Meloni was technically unofficial, coming as it did ahead of a three-day peace conference that concluded with a speech by Pope Francis, who also met privately with Mr. Macron.

Mr. Macron and Ms. Meloni had previously sparred over  immigration, and their hour-long encounter on Sunday was described by La Republica as a “forced thaw.” The two leaders met at a luxury hotel terrace overlooking Vatican City on Sunday night and reportedly spoke for a little more than an hour about Europe’s  economic challenges related to the war in Ukraine and the management of migratory flows.

In a video from 2018, Ms. Meloni was seen chiding Mr. Macron over his criticisms of the Italian stance on illegal immigration. In  June of that year, Italy had refused to grant port access to a ship plying the Mediterranean with several hundred rescued migrants on board. The incident with the Aquarius sparked a crisis in the normally amicable relations between the two European powers, with Matteo Salvini’s Northern League and Ms. Meloni’s Brothers of Italy party blasting France as a symbol of hypocrisy.

To make matters worse, Mr. Macron then took aim at Italy’s populist parties — which now compose the country’s governing coalition — as a tool to sharpen his own liberal European political identity and differentiate him from his longtime domestic foe on the right, the leader of the National Rally, Marine Le Pen. She could turn out to be less forgiving of Mr. Macron’s liberal, Euro-centric brand of  politics than Ms. Meloni.

The latter, after all,  is starting out fresh and needs as many allies as she can get as she seeks to show the rest of Europe that she can be taken seriously, that her right-of-center platform poses no threat, and that she can keep in working order her somewhat fractious coalition partners, which also include a loose-lipped ex-premier and press baron, Silvio Berlusconi. Ms. Le Pen’s antipathy toward Mr. Macron, whose approval ratings are plummeting, is only growing. 

While Mr. Macron was making the rounds at Rome on Monday,  Ms. Le Pen in a surprise maneuver teamed up with her putative rivals on the left to table a no-confidence vote against the French president. At issue was next year’s national budget: Without a majority in the National Assembly, Mr. Macron’s government was not able to pass it with a vote, forcing it to use an emergency political mechanism to push it through. Doing so not only led to Ms. Le Pen’s voting for a motion of a censure, but to a separate motion being put forward by the left-wing France Unbowed party of Jean-Luc Mélenchon.

Marine Le Pen and Mr. Mélenchon have both run for the presidency of France three times. In the 2022 election that saw Mr. Macron clinch his second five-year term, Ms. Le Pen finished second. After announcing her party’s vote to censure Mr. Macron on Monday, she also added, “If tomorrow we have to go to the polls again, we are ready to do so.”

That is as clear a warning shot as any to the present occupant of the Palais Elysée. If the vultures are circling for Mr. Macron at Paris, it may be the birds of prey are taking their cues from other beasts in European menagerie. The biggest one is President Putin, with whom Mr. Macron infamously tried to establish a rapport — at least diplomatically — early on in Russia’s invasion of Ukraine but who according to the Russian press is no longer taking calls from the floundering Frenchman. 

Then there is Britain’s new prime minister, Rishi Sunak, who at 42 is two years younger than Mr. Macron. Ms. Meloni’s ascent has put Italy in the limelight momentarily but the center of political gravity in Europe is pivoting back to London. Some of Mr. Macron’s detractors at home have already criticized his trip to Rome as premature and little more than a photo opportunity. To take the more charitable view, solid Franco-Italian relations are important, especially amid more signs of German equivocation on support for Ukraine. 

Meantime, rising inflation and Mr. Macron’s plans for pension reform and reducing the age of retirement all but guarantee more rage and labor unrest in France. Paired with mounting public discontent with a government increasingly perceived as detached from reality, Mr. Macron may be wishing he could stretch his petite Roman holiday into a retirement of his own.