David A. Andelman, member of the board of contributors of USA Today, is the author of "A Shattered Peace: Versailles 1919 and the Price We Pay Today." He formerly served as a foreign correspondent for The New York Times and CBS News. Follow him on Twitter @DavidAndelman . This opinions in this article belong to the author.

(CNN) France's 39-year-old President Emmanuel Macron is poised to wind up as the most powerful leader in Europe -- in the wake of Theresa May's stunning election blow in Britain and his fledgling party's landslide win in the first round of France's parliamentary elections.

Despite the two-round nature of French elections, Macron's year-old La Republique en Marche party is estimated to win between 415 and 445 seats of the 577 seats in the National Assembly, assuring him of an overwhelming majority to work his will on a nation, indeed a continent, lusting for change.

The old-line center-right Les Republicain party is expected to win barely 80 to 100 seats . The Socialists, who controlled both the presidency and the parliament for five years until the popularity of Macron predecessor's Francois Hollande, slipped to single digits and scored the lowest vote in the party's history, barely 30 to 40 seats. Even the far-right National Front of Marine Le Pen is expected to snag 10 to 20 seats by the time the second round of voting ends next Sunday.

So it would appear voters have overwhelmingly bought into Macron's style of leadership of France, Europe and perhaps the entire Atlantic alliance.

With less than a month in office himself, the way Macron has stood up to US President Donald Trump and Russian President Vladimir Putin, and held his own with German Chancellor Angela Merkel, has endeared him to millions of French voters. His quick response to the latest terrorist incident at Notre Dame Cathedral also suggests he is capable of managing France's most acute problems. Moreover, the election seems to mark a true generational shift in France with more than 800 candidates for the National Assembly under 30 years old.

Macron has very much hit the ground running at home and abroad. When a lone terrorist lashed out with a hammer against a French police officer in front of Notre Dame, Macron promptly proposed ending the 14-month-old state of emergency, while enshrining some of its toughest provisions permanently in French law, including house arrests and property searches without warrants. These changes would also allow outlawing of protest marches and shuttering houses of worship suspected of encouraging extremist views.

In an effort to shrink France's ballooning unemployment -- now hovering above 10% overall , but above 25% for the young people who are his most ardent supporters -- Macron has crafted a dramatic reform of the entire labor system. His party plans to cram through legislation and executive orders to curb embedded costs of hiring and firing that are seen as brakes on growth. Now, companies that see their sales and profits fall can dismiss workers or change the nature of their work force to conform to the marketplace. Such measures could bring more young unemployed into companies, while sharply increasing economic growth.

Abroad, Macron is also well positioned to return France to a leadership role in Europe and the world. With the Trump administration apparently deeply divided on how to approach the sudden, potentially catastrophic rift between Qatar and the rest of the Sunni-dominated Middle East, Macron quickly phoned the Emir of Qatar, Saudi Arabia's King Salman and Iran's newly re-elected President Hassan Rouhani and offered to mediate the dispute between Sunni and Shiite, cutting Trump effectively out of the mix.

He'd already summoned Putin to a face-to-face meeting at Versailles, telling the Russian leader the use of chemical weapons in Syria was a red line, then rebuking Putin for his abuse of gays and dissidents, while offering no relief from sanctions that all Europe accepts. At the same time, he announced his support for an EU military force , giving voice to fears across Europe that the United States can no longer be trusted to come to the aid of any NATO ally.

Throughout, Macron has run a savvy, low-key legislative campaign. His last full day of campaigning on Friday began with a visit to the switchboard of the Elysees presidential palace where he took calls that were filmed and promptly Facebooked and tweeted -- wishing a happy birthday to a young high school student and luck on his baccalaureate exam, and explaining to a retired couple how they'd wind up "winners" under core elements of his social program that includes a rise in social security taxes combined with a drop in the residence taxes for 80% of households. "This is a great barometer," he said, smiling, to the telephone operators as he departed. He then headed out to the countryside, assuring farmers their voices would be heard, "that you will be able to earn a living from your work."

Indeed, each segment of the vast and suffering population of France has heard something encouraging from this President during his first month in office.

Macron's spanking new Parliament must now prepare to execute these laws against the inevitable protests from a population for whom opposition and demonstrations are a way of life. Still, his campaign has suggested that he has both the temperament and, even at his tender age, the political sagacity to manage the delicate balancing acts that have eluded French presidents twice his age.

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Throughout the monthlong legislative campaign, Macron's party slogan was "donner une majorite au president" (give a majority to the president). A substantial number of his candidates have never before run for public office of any type and include a retired female bullfighter, fighter pilot, paramilitary police commander and handball champion, plus a host of small-business owners.

As a result, the early days of the National Assembly could be most interesting, with a whole lot of stumbling around in the dark, or the government itself, populated by a number of ministers with some real experience, driving the agenda, which is a complex and vital one.

After Sunday's vote, however, it would appear the world is acquiring a new set of major regional leaders. The French President, his government and the nation he leads are becoming a significant force in Europe. And the United States will need to find a way of accepting, even celebrating, the new reality that it no longer is Number 1 anywhere.