A commission appointed by Congress will recommend that expanding selective service registration to women is a “necessary and fair step.” By Sarah Mervosh and

Women have been serving the United States military for generations, sewing uniforms during the Revolutionary War and nursing the wounded during World War II. They have flown fighter jets, commanded warships and more recently fought in combat on the front lines.

But they have never been required to register for a military draft.

That could soon change. Under a new recommendation to Congress by a national commission, all Americans ages 18 to 25 — not just young men as currently required — would have to register with the government in case of a military draft.

The recommendation, part of a report that will be released to Congress on Wednesday, represents the final stage in a divisive debate that has been simmering for decades: Should the United States have a military draft, and should it include women?

“The biggest piece of opposition was, we are not going to draft our mother and daughters, our sisters and aunts to fight in hand-to-hand combat,” said Dr. Joseph Heck, chairman of the commission, which held dozens of public meetings and considered more than 4,000 public comments over the past two years.

But as women have increasingly taken on a larger presence in military life and culture — making up about 17 percent of active-duty troops — commissioners concluded that expanding the registration process to include all Americans in the event of a draft was a “necessary and fair step.”

It was not immediately clear when the House or Senate might consider such a measure. A representative for the Pentagon declined to comment.

Should Congress adopt the recommendations, it would mean that women ages 18 to 25, like young men, would be asked to register with the Selective Service System, the independent government agency that maintains a database of Americans eligible for a potential draft.

Instead of requiring a trip to the post office, registration today often happens automatically when a young adult applies for a driver’s license or federal financial aid. But no one can be required to serve unless a draft is enacted, a step that would require an act of Congress and approval by the president.

“Women bring a whole host of different perspectives, different experiences,” said Debra Wada, a former assistant secretary for the Army who served on the commission, noting that being drafted does not necessarily mean serving in combat. In a time of national crisis, the government could draft people to a variety of positions, from clerical work to cybersecurity.

“If the threat is to our very existence,” she said, “wouldn’t you want women as part of that group?” To many, the draft itself may seem moot: No one has been forced into military service in more than 40 years. The modern-day military has been successful as an all-volunteer force, with about 1.2 million active-duty troops.

Still, the draft has been a controversial topic since the Vietnam era, when thousands of young men were conscripted into military service, sparking protests as the war dragged on. President Trump himself received five draft deferments. Not registering with the Selective Service can come with a lifetime of penalties, including exclusion from student loans or the chance to work for the federal government.

“Congress should end draft registration for all, not try to expand it to young women as well as young men,” a group of activists who oppose the draft said in a joint statement on Tuesday. It added, “Even more women than men would resist if the government tried to draft them.”

The commission recommended that the United States keep a draft option in place as a “low-cost insurance policy against an existential national security threat,” Dr. Heck said.

The question of whether to include women in a potential draft became more urgent in recent years, after the Pentagon announced in 2015 that it would open all combat jobs to women. Since then, more than 2,000 women have served in Army combat positions, and today, more than 224,000 women serve on active duty.

“Women have proven themselves since 9/11 as pilots, medics, military police, engineers, and as part of the special operations and intelligence communities,” said Phillip Carter, a former Army officer and veteran of the Iraq war who is now a scholar at the RAND Corporation. “If America resorts to a draft to mobilize for war again, the experience of the past 18 years shows that the nation can and should rely on women to fight too.”

In 2016, some military leaders openly advocated for requiring women to register with the Selective Service. The same year, the Senate majority leader, Mitch McConnell, said he supported making the change. The Senate briefly considered the question, but a provision for it was ultimately removed before it reached President Barack Obama.

While reinstating the draft is generally unpopular and seen as a last resort, polls show that the American public is split about whether women should be eligible, with about 52 percent of Americans in favor. More women than men were opposed to making the change, according to a 2013 poll by Quinnipiac University.

Mr. Heck, the commission chairman and a former Nevada congressman, said he was confident that the issue would be taken up in both the Senate and the House. “Where it goes from there,” he said, “is a matter of debate.”