PARIS — When President Emmanuel Macron repeatedly declared “war” on the coronavirus in March, he solemnly promised that France would support “front-line” health workers with “the means, the protection.”

The reality was that France was nearly defenseless.

The government’s flip-flopping policies on past pandemics had left a once formidable national stockpile of face masks nearly depleted. Officials had also outsourced the manufacturing capacity to replenish that stockpile to suppliers overseas, despite warnings since the early 2000s about the rising risks of global pandemics.

That has left France — unlike Germany, its rival for European leadership — dependent on foreign factories and painfully unable to ramp up domestic production of face masks, test kits, ventilators and even the thermometers and over-the-counter fever-reducing medicines to soothe the sick.

Today, as it has begun loosening one of the world’s strictest lockdowns, France has become a case study in how some countries are now reconsidering their dependence on global supply chains built during the past two decades on the mantra of low costs and quick delivery. Even now, France has no guarantees that it can secure enough supplies in the coming weeks to protect against a potential second wave of the virus.

“In times of crisis, we can no longer switch from one production zone to another to get our essential products,” Louis Gautier, the former director of the General Secretariat for Defense and National Security, a powerful inter-ministerial unit inside the prime minister’s office that coordinates the response to large-scale crises, said in an interview. “The issue of strategic stocks and secure supplies has to be reconsidered. A new model has to be invented.”

France had long identified masks as indispensable in a pandemic yet the government had mostly stopped stockpiling them during the past decade, mainly for budgetary reasons. Domestic production collapsed at the same time the country’s pharmaceutical industry was also moving overseas.

France had decided “that it was no longer necessary to keep massive stocks in the country, considering that production plants were able to be operational very quickly, especially in China,” the health minister, Olivier Véran, said in Parliament in March.

But the scope and speed of the coronavirus defied that logic. Still reeling from its own outbreak, China, the world’s leading maker of masks, was overwhelmed with orders. India, a top exporter of medication, temporarily banned exports for fear of shortages.

As the globalized supply chain broke down, French health officials lost critical time as the national government — as well as cities, towns and even wards — scrambled to buy supplies directly from China and elsewhere. The government organized highly publicized airlifts of masks from China, betraying both its desperation and its dependence.

France has suffered more than 27,000 deaths and one of the world’s highest fatality rates, 60 percent greater than in the United States.

“We will have to rebuild France’s agricultural, health, industrial and technological independence,” Mr. Macron said in a recent address.

To many critics, France’s defenselessness in face of the virus was the logical conclusion of the hollowing out of France’s manufacturing base — a transformation that has deepened inequality and fueled violent protests, like the Yellow Vest movement.

In the early 2000s, Germany had a slight edge over France in manufacturing and exporting PCR test kits — the most widely used today to detect the virus — and oxygen therapy equipment, according to United Nations data. But by 2018, Germany had a $ 1.4 billion trade surplus for PCR test kits whereas France had a deficit of $ 89 million.

While Germany was able to quickly mobilize its industry to fight the pandemic, France was paralyzed. It couldn’t carry out large-scale testing because it lacked cotton swabs and reagents, low-value but crucial elements that had been outsourced to Asia.

“France has deindustrialized too much since the 2000s — it’s paying for it today,” said Philippe Aghion, an economist who teaches at Harvard and Collège de France.

In a still unpublished study, Mr. Aghion and economists at the Free University of Brussels found that over all, countries with the capacity to manufacture test kits and related instruments, like Germany and Austria, had so far suffered fewer deaths during the pandemic.

In France, shortages have affected even basic goods. Drugstores ran out of thermometers. Supplies of paracetamol — a common pain reliever sold as Tylenol in the United States — became so dangerously low that the authorities restricted its sale.

The last European factory producing the medication was in France, near the city of Lyon, but it closed in 2008, according to France’s National Academy of Pharmacy. The association has long warned of France’s growing dependence on foreign drugmakers, noting that 60 to 80 percent of active pharmaceutical ingredients in Europe are imported — compared with 20 percent three decades ago.

“Nothing has been done at the government level to stop this,” said Marie-Christine Belleville, a member of the academy.

Warnings, in fact, had been issued for years.

In the aftermath of the SARS pandemic in Asia in 2003, French officials analyzed the risks in a series of reports and built up a national stockpile of masks and other protective equipment manufactured by domestic suppliers — in keeping with a Gaullist tradition of maintaining a strong domestic defense industry that also exports Rafale fighter jets, submarines, minesweepers and frigates to the world.

In 2006, a government pandemic plan recommended a series of measures, including creating stockpiles of masks. A year earlier, France’s Health Ministry signed a five-year contract to buy 180 million masks a year that Bacou-Dalloz, then the biggest mask manufacturer in France, would produce at a factory in Plaintel, about 280 miles from Paris.

Details from the contract, a copy of which was obtained by The New York Times, reveal the government’s strategic thinking at the time. Securing a domestic supplier would help France avoid being “exclusively dependent on importations that would be disrupted in the context of a pandemic.”

The contract would ensure the government’s “renewal of its stockpile of masks” as older stocks reached their expiration date. And during a pandemic, the government could requisition the plant’s production.

The government order “monopolized the Plaintel factory’s entire production capacity,” said Jean-Jacques Fuan, a former director of the plant.

By 2008, the government issued a white paper that for the first time cited pandemics as a potential national threat, ranking it fourth behind terrorism, cyberwarfare and a ballistic missile attack.

“In the next 15 years, the arrival of a pandemic is possible,” the paper warned. It could be highly contagious and lethal, it said, and could come and go in waves for weeks or months.

But soon afterward, many politicians began criticizing the policy of stockpiling masks and medication as wasteful. About 383 million euros spent in 2009 on acquiring 44 million vaccinations against the H1N1 flu caused a political scandal after less than 9 percent of French people were vaccinated.

In 2013, the General Secretariat for Defense and National Security issued new pandemic directives emphasizing “overall savings” and reducing the importance of maintaining a stockpile. Surgical masks would be stocked, but not the more sophisticated FFP2 masks that, the report noted, cost 10 times as much.

The directives also transferred the responsibility — and costs — for securing and stockpiling masks to public and private employers. This contributed to the severe shortages that France has suffered in recent months, as government officials became less engaged on the issue.

Mr. Gautier, the former director of the general secretariat, said that the new directives had been intended to improve the distribution of masks by requiring employers, like hospitals, to stock them and to make them legally responsible for the protection of their employees.

But he acknowledged that “it would have been logical to transfer the credits and not only the costs to the employers. We should have also put in place measures of control to ensure that the reforms had been applied correctly.”

But the new policy also undermined France’s capacity to produce masks. Employers, now charged with procuring masks, naturally sought cheaper suppliers abroad.

And to save costs, the government placed large orders that only Chinese factories were able to satisfy, said Francis Delattre, a former senator whose 2015 report warned of the depletion of masks.

“Small French factories were losing orders,” Mr. Delattre said. “It was very dangerous to entrust only one or two Chinese conglomerates with the health protection of the country.”

And without its single government customer, the factory in Plaintel, which had once been running 24 hours a day, saw its business shrivel and eventually closed in 2018, Mr. Fuan said.

As expired masks were disposed of, France’s national stockpile shrank from 1.7 billion in 2009 to 150 million in March.

And as the “invisible enemy” began rampaging throughout France, the country that made some of the world’s most sophisticated military hardware in the world was unable to produce enough face masks.

“This crisis must lead us to consider health care as a strategic sector that should draw on a lot of what we do in defense,” said Arnaud Danjean, a European lawmaker.

“We weren’t armed for this,” he added.