The fraying of relations between France and Italy is extraordinary. These are two west European countries who are neighbors, allies and - from fashion to football, tourism to culture - marquee names on the continent. The dispute is all of Italy's making. It was Deputy Prime Minister Luigi Di Maio's decision to show up unannounced near Paris last week for a meeting with a prominent yellow vest protester – one of the tens of thousands of demonstrators who have repeatedly sparked violence in Paris. Di Maio has been on record as calling for the military to oust French President Emmanuel Macron. This is stunning interference. As for the visit, the least the Italians could have done was notify the French government. It was a surprise even to Italy's Foreign Ministry. Before that provocative visit, there had been a series of increasingly personal slurs leveled at Macron by Di Maio and Italy's other Deputy Prime Minister Matteo Salvini. The two formed a populist coalition government last year made up of the far-right League and anti-establishment populist Five Star Movement (M5S). Both Di Maio and Salvini hope to score big in European parliamentary elections in May, so they hope to recapture the anti-establishment spirit that carried them to victory last year, as evidenced by their enthusiastic support for the yellow vest protests. On the other side stands Macron who is attempting to rally Europe's liberals against populist nationalists gaining ground across the continent. Macron, after all, was elected as a shield against the populist, far-right politician Marine Le Pen. If he was victorious in France, Macron believes his influence could spread to the rest of Europe. In last year's general election, the M5S became the largest individual party in the Italian Parliament and with the League heralded an administration with the toughest line on immigrants in Italian postwar history. Consequently, it is no surprise that the origin of the dispute is immigration, including migrants trapped at the Franco-Italian border, and in general how to handle the influx of migrants crossing the Mediterranean for Europe. There is also the already festering dispute over the complex peace process in Libya, where Paris and Rome are vying for the role of chief negotiator. Di Maio claims the yellow vests are a sign that the winds of change are sweeping across the Alps, and that Macron, a "bad president", will, as a result, be defeated, leading to broader changes in the European parliament. All this means that at least until the May elections, reconciliation is unlikely. The recall of the ambassador to Rome, the first since Benito Mussolini declared war on France in June 1940, is symbolic and most likely temporary but nevertheless a real diplomatic shocker. It is an astonishing deterioration in relations between Rome and Paris, just 13 months after Macron and Italy's previous government announced plans to sign a Franco-Italian friendship treaty. Di Maio and Salvini apparently underestimated the consequences of their repeated punches at Macron. Given the economic and commercial ties between the two countries, the French could make Italy pay dearly. Italy is less powerful. It is in a recession and heading for only 0.2 percent growth this year. Already some businesses that co-operate across the Franco-Italian border are uneasy. Alitalia is hoping for French capital to save the airline while infrastructure plans such as the Turin-Lyon high-speed rail link are in doubt. France is Italy's second biggest trading partner, after Germany, and Italian exports to France outweigh French exports to Italy by more than €10 billion a year. The League and Five Star vow to bury traditional politics for good, but there are diplomatic norms that remain sacrosanct. One cardinal rule: A country should never interfere in the internal affairs of another, certainly not a neighbor, ally and important trading partner. Italy's populist leaders have done just that, crossing a clearly marked red line.
