By Nicholas Kristof of The New York Times

Ukraine is a traditional and sexist society caught in a grueling artillery war with Russia, so the last person you’d expect to see in an army uniform is a grandma.

But Mariia Stalinska, 41, a bookkeeper whose first grandchild was born a year ago, enlisted in the army after Russia invaded her country in February.

“We need to defend our children,” she told me. “If not us, who?”

While registering for military service is compulsory for men, women can choose to volunteer. After the invasion, many did so, and almost 60,000 women are now in the Ukrainian armed forces, sometimes filling combat roles.

“I won’t be in an office somewhere,” said Liliia Fedorenko, 45, who signed up on the morning of the invasion. “I’ll be in the trenches, shooting, doing reconnaissance.”

“I’m a good shot,” she added.

The determination of Ukrainian women to fight Russians, or spy on them from behind enemy lines or raise money for the troops reflects an unflinching determination of Ukrainians, male and female alike, to sacrifice for their country. At a time when the United States is so divided, Ukraine feels the opposite: There is a passionate, uplifting, leveling unity here, and it’s one reason Vladimir Putin may be in trouble.

The Ukrainian government says that 151 female soldiers have been killed or are missing so far. About 350 have received awards such as “Hero of Ukraine.”

Today in the war in Ukraine, the sexism of Russian troops may have hurt them, because they did not always realize what women are capable of.

“They were not suspecting women,” said a female community leader in the Kharkiv region who defied and misled Russians when her area was occupied. She did not want her name used in case the Russians return.

The involvement of women is a reminder that half the human resources in any society are female, even if countries don’t always appreciate that. Harness the unfulfilled potential of half the population, and any nation will gain an edge.

The rush of female soldiers is so new that Ukraine’s military doesn’t even have standard uniforms for women, so women were stuck with ill-fitting uniforms designed for men. They protested that warriors come in all genders and that uniforms should be able to accommodate female hips and chests.

One of the early female volunteers, Anastasiia Kolesnyk, a 25-year-old marketer who signed up on the first day of the war along with her boyfriend, complained to family members, who found better-fitting uniforms for her and her friends.

Other women asked for them as well, and the family effort ballooned into a nonprofit, Zemliachky, that received a torrent of donations to buy uniforms, body armor, thermal underwear and other gear for female soldiers. It has a warehouse in Kyiv with clothing and equipment it is supplying free to women.

Attitudes toward the female soldiers seem to vary with commanders. “I heard, ‘You’re a woman, you need to make babies, go home,’” said Anastasia Blyshchyk, 26, who initially was rebuffed when she volunteered. Rather than sitting on a long waiting list to serve, like many other Ukrainians, she reached out to commanders and found one who said he could use her.

She now wears a uniform with an unofficial shoulder patch, right below the Ukrainian flag, reading: “ARM WOMEN NOW.”

While women can also serve in the Russian military and intelligence service, few women appear to be in Russia’s invading force in Ukraine.

Women also seem to have been very effective as spies behind enemy lines, using their phones to report on Russian troop locations and movements.

“I really wanted this area to be liberated,” said Albina Strelets, 33, explaining why she spied on Russian forces and transmitted information to the Ukrainian side. She was arrested and spoke to me above the jail and torture chamber where Russians detained her for 16 days in August.

Other prisoners were tortured, raped and killed, she said. She added that she bluntly told her interrogator, a Chechen, that she supported the Ukrainian side in the war, winning his grudging respect.

“You have balls of iron, more than most men,” he told her, by her account. She said she was not physically harmed.

Female spies aren’t new, of course. A relative of mine, Izabela Krzysztofowicz Jaruzelska, was a sworn member of the Polish resistance during World War II. She was involved in a Polish courier network that gathered intelligence on the Nazis, carried it through what is now Ukraine and transmitted it to the Polish government in exile in London, but she was caught, sent to Auschwitz and died there in 1943.

An open question is whether the heroism of so many women in this war will chip away at traditional sexist attitudes and create a more equal society afterward. Will Ukrainian men be more likely to treat their wives as equals? One indication of possible progress is that almost half of all new small businesses since the invasion were started by women.

“This will change the role of women in society,” said Alla Kuznietsova, who spied on the Russians during the occupation of Izium and reported regularly to the Ukrainian side.

“Not every woman will take a gun and fight, but we do everything possible to help the army,” said Kuznietsova, who recounted having survived brutal torture and rape at the hands of Russian interrogators. “I have two good female friends who were doing the same.”

“Of course this will change things.”