Paris, the world gave you the Olympic truce for which President Macron asked — but now it’s au revoir to all that. Things previously swept under the carpet for a couple weeks of international kumbaya are now aswirl, some inextricably linked to events in the Middle East.

Antisemitic incidents, a staple of modern French life, are multiplying. On August 15, just days after the Olympic games concluded, a man was filmed hurling antisemitic remarks at a woman riding the metro in the 16th district of Paris — one of the capital’s toniest neighborhoods. According to footage evaluated by French police, the aggressor’s insults included “Hitler was right” and “you’re going to pay” as well as the additional libel of “you’re committing crimes against humanity.”

The latter comment has also been reverberating through some of the more left-wing echelons of French power — or would-be power, as, with the exception of President Macron, France is still listing under the strains of  a caretaker government. 

It is a prolonged temporary situation that is a holdover from the tumultuous second round of snap legislative elections last month, which resulted in a reversal of fortune for a center-right alliance led by the National Rally and the resignation of the prime minister. 

Within that time, a member of the radical left France Unbowed party, 32-year-old Rima Hassan, found time to march in a pro-Hamas demonstration in Amman, Jordan. Specifically, according to the French news magazine Le Point, Ms. Hassan joined a rally that paid tribute to the late Hamas political figure Ismail Haniyeh, who was assassinated in Iran on July 31.

The march took place not long after that, and on August 16, Ms. Hassan and a companion said to be “close” to France Unbowed  posted videos of their participation on various social media networks. Some of the demonstrators can be heard chanting in Arabic, “We are coming, oh Aqsa” — a common slogan among Islamic fundamentalists  which means that they intend to take control over what for them is a sacred mosque at Jerusalem.

Also seen in the videos are posters with messages that appear to offer high praise for Ahmed Yassin, the founder of the Hamas terrorist group who was assassinated in 2004. 

Even more problematic for Paris is that Ms. Hassan is a member of the European Parliament. Before her election to that body of enduringly questionable utility, judicial police investigated her for “apologizing for terrorism.” Prior to that, in response to a question from another French press outlet as to whether Hamas was waging a legitimate war, she replied with a terse “true.”

However, and also in April, the left-leaning Le Nouvel Obs featured a profile of the politician in which she said she condemned “the terrorist attacks” by Hamas. Her seemingly jubilant presence at a gathering of Islamic extremists in Jordan just weeks ago, however, belies the sincerity of what appears to be a soundbite-style condemnation. 

Not for the first time in France, anti-Israeli sentiment and unadulterated, loosely  tolerated antisemitism are metastasizing into something bigger. At the end of July, the head of  France’s Républicains party, François-Xavier Bellamy — who is also a European parliamentarian — lodged a complaint against Ms. Hassan for alleged threats. 

On her X account, she had written, “For the moment, François-Xavier Bellamy and his little friends, close to the genocidal Israeli regime, are sleeping well at night. It’s not going to last.”

Mr. Bellamy’s complaint was enough for the European Parliament president, Roberta Metsola, to open an investigation to determine whether  Ms. Hassan violated the institution’s code of conduct. 

Meanwhile at Paris, a member of Mr. Macron’s Renaissance party and European parliamentarian, Caroline Yadan, stated that Rima Hassan is a “poison of hatred” who “cannot decently sit within our democratic institutions, at our expense and at the expense of our republican values.”  Ms. Yadan is calling for Ms. Hassan’s parliamentary immunity to be lifted. 

All this comes as the France Unbowed party is exerting pressure on President Macron to make  Lucie Castets the country’s new prime minister. Ms. Castets was nominated for the position by the left-wing New Popular Front. France Unbowed, which is part of that broad but somewhat shaky alliance, has threatened to take steps to remove Mr. Macron from office if he fails to comply. 

While technically feasible, in practice that would be a tall order, and it is not likely the reliably stubborn Gaul will yield to that kind of pressure.  In the meantime, a rumble is shaping up ahead of a rumored rendezvous Friday between Mr. Macron and the virtually unknown Ms. Castets. 

Writing on X, Marine Le Pen asked “In what capacity is Lucie Castets claiming to attend Friday’s meeting at the Elysée Palace, intended for party leaders and chairmen of parliamentary groups in the National Assembly and the Senate?”

Ms. Le Pen appears to be gently accusing the NPF of organizing a coup, of sorts. Given the French left’s unimpressive — understatement — track record on support for Israel and France’s beleaguered Jewish community, it would come as no surprise if the three-time French presidential contender were on to something.