BRUSSELS — Should Marine Le Pen prove the polls wrong and win the French presidency on Sunday, she would immediately represent a severe danger to both the European Union and NATO.
France is the European Union’s second-largest economy, its sole nuclear power and its only permanent member of the United Nations Security Council. It is at the heart of European financial and security policy and is a key member of NATO.
To have a far-right populist with close ties to President Vladimir V. Putin as France’s regal president would be destabilizing enough, but it would be an earthquake in the middle of Russia’s unprovoked war against Ukraine.
In France, the president is the prime actor on foreign and defense policy, so even if her party fares badly in the legislative elections in June, Ms. Le Pen would still be able to carry out many of her intentions.
Those goals would include leaving NATO’s integrated military command, reinstating border controls and affirming the superiority of French law over European law, which would challenge one of the bases of the European Union and put France in the same boat with Hungary and Poland in questioning the primacy of European law.
“Should Le Pen be elected, the European Union and NATO would instantly become weaker — some even speak of ‘collapse’ — and it would represent the culmination of Russian support to France’s extreme right,” Marc Pierini, a former E.U. diplomat, wrote for Carnegie Europe. “It would also represent Putin’s biggest strategic victory against NATO and the E.U., along with Russia’s expanded military deployment in the Mediterranean area since 2015 and its delivery of S-400 missiles to Turkey in 2019.”
Her victory would also be a counterreaction to one of Mr. Macron’s most important policy goals: to increase European integration, in terms of finance and defense. And it would damage both.
Given the need for unanimity in the European Union, she would also undermine, if not end, Europe’s ability to create and sustain economic sanctions against Russia.
The prospect of a Le Pen victory, however unlikely, is real enough that the leaders of Germany, Portugal and Spain — Chancellor Olaf Scholz, Prime Minister António Costa and Prime Minister Pedro Sánchez — took the highly unusual and undiplomatic step in an opinion article in Le Monde of implicitly urging French voters to reject Ms. Le Pen.
Interfering in the domestic politics of other countries is normally a no-no, but clearly they considered the danger to be severe.
“The second round of the French presidential election is not, for us, an election like the others,” they wrote. “The choice facing the French people is crucial for France and for all of us in Europe.”
Without directly urging the French to vote for Mr. Macron and against Ms. Le Pen, they left no doubt about where they stood.
“It is the choice between a democratic candidate, who believes that France is stronger in a powerful and autonomous European Union, and a far-right candidate, who openly sides with those who attack our freedom and our democracy — fundamental values that come directly from the French Enlightenment,” they wrote.
Such intervention does not always go down well. President Barack Obama intervened in the debate over Brexit before the 2016 referendum to suggest that if Britain left the European Union, the country would be “at the back of the queue” for a trade deal with Washington.
While it is unlikely that his comments significantly swayed the vote, they were a subject of great controversy and criticism, and voters ultimately disregarded his wishes.