Yelena Koval, 47, worries about her 25-year-old son serving in the Ukrainian army. “Our boys are heroes,” she said on Aug. 1. “But I don’t need my son to be a hero. I need him to be alive.” (Carol A. Morello/The Washington Post)

The calls home from the front line are very brief, often just two words conveying all that really matters.

“I’m alive,” Marina Bershadskaya’s little brother, Sergey, tells her. Then he hangs up to pass the communal cellphone to one of his fellow paratroopers in the 79th Airborne Brigade, deployed to Ukraine’s border with Russia.

It has been this way for almost three months, especially in the past few weeks, amid a major Ukrainian offensive against pro-Russian rebels in the east. Even as each day brings Ukrainian gains and the map of rebel-held territory shrinks, the calls have seeded a gnawing fear in the families of troops positioned in the thin, treacherous buffer zone between Ukraine and Russia in the rebel strongholds of Donetsk and Luhansk.

Their mission is to stop men and equipment from crossing into Ukraine from Russia via the porous border. They are surrounded by enemies, largely hemmed in by land mines laid by rebels. When bombarded by separatists, they shoot back. But when the artillery fire comes from Russia, they cannot respond.

Most of the fire is directed from Russian territory.

Irina Vidayeva, top left, comforts the crying mother-in-law of a soldier on the front line. As Vidayeva spoke with her husband on speakerphone from the front each of the women — all a sister, wife or mother of a soldier-- cried. (Carol A. Morello/The Washington Post)

The heavy fighting is taking a toll on the Ukrainian military, which was severely diminished in the two decades after the nation became independent in 1991. The military is growing stronger with experience, a rush of volunteers and three partial mobilizations of trained reservists and soldiers who completed their required army duty.

But there are hints of the war’s intensity that cannot be measured in towns retaken and rebels disarmed. Last week, a group of about 40 men from Ukraine’s 51st Mechanized Brigade crossed into Russia. They have since returned to Ukraine of their own volition and at least some are being accused of desertion.

A plea for more assistance

Although no discernible antiwar movement is afoot, a growing number of wives, mothers and sisters of service members are traveling to Kiev, the capital, to agitate for needed reinforcements, more supplies and battlefield breaks. The most active have been women connected to the infantrymen in the 72nd Brigade and the paratroopers of the 79th, both at the border and under almost constant fire.

About 40 women arrived by bus last week from Mykolaiv, a port city on the Black Sea where the 79th is based. Rather than split up and stay in private homes, they are encamped in a military building called Officers House, where hallways are painted with murals of troops marching into battle. They sleep in conference rooms on air mattresses provided by the governor and a member of parliament from Mykolaiv, and take their meals in a parking lot beside the chartered bus that brought them to Kiev.

They are there on behalf of an elite cadre of men. The 79th is a proud unit, whose motto is “Nobody But Us.” One unit member has attached a GoPro camera to his helmet and posts his battlefield videos of artillery attacks. He sounds a defiant note, writing recently, “Let the dogs who came to our land consider, they will be destroyed and eaten for lunch.”

The messages to loved ones are more nuanced.

Grad rockets fired from Russia and by separatists inside Ukraine land almost every day and night. The soldiers huddle in bunkers for protection.

“They’re digging holes, like rabbits,” said Yelena Koval, 47. Her 25-year-old son, Konstantin, told her that they bring the bodies of their fallen fellow soldiers into the bunkers with them so their corpses will not be fired upon again and become unrecognizable. Some soldiers say they are having hearing problems because of all the explosions. Others awaken from nightmares of being under attack.

Convoys bearing supplies arrive only intermittently down roads unprotected from shelling and lined with trees hiding snipers in their thick greenery. Bershadskaya said when a soldier bringing them food died after being hit by shrapnel, the 79th asked for the convoys to stop so its solders wouldn’t have any more deaths on their consciences. They stretched out their remaining food supply, with four men sharing one ready-to-eat meal a day.

Many of the women believe their men will need psychological help when the war ends.

Oksana Tsvetko, 27, sometimes feels as if she doesn’t recognize her husband, who was in the army when they met 11 years ago.

“They are paratroopers and they will never surrender, they will never ask to get out,” she said. “But he’s very tired. Sometimes it’s like it’s not him speaking.”

In one recent call, he kept saying, “Everything is burning. Everything is burning. Everything is burning.’”

‘Our boys are heroes’

Suddenly, Irina Vidayeva’s cellphone rings. It is her husband, Yevgeniy, a 29-year-old captain with the 79th. She puts him on speakerphone so that the dozen women crowded around the chartered bus can listen in.

“Two days ago, we took out four Russian trucks, one tank and an armored personnel carrier crossing the border,” he says on a phone line that crackles with static.

“We’re not under fire now, but in the night we were shot at by artillery and Grads. It lasted for 3 1 / 2 hours. It came from Russia. It’s not coming from the Donetsk People’s Republic or the Luhansk People’s Republic. Sometimes the DPR and the LPR fire at the Russians, trying to provoke them to fire back. . . . But we’re under strict orders not to fire into Russia. If we shell them, they will attack us.”

The women stand in silence, tears running down their cheeks.

Saturday was Paratroopers Day in Ukraine, and President Petro Poroshenko issued a statement calling paratroopers “the embodiment of dignity and honor to their country and their people. They have covered themselves in glory.”

With a mobilization calling up an estimated 60,000 troops for 45 days, the Ukrainian military is rotating out some front-line troops. Andriy Lysenko, a military spokesman, said troops with the 79th will be among them. But some will be kept at the front, where their experience is needed.

“The situation is difficult because they can’t fire back at the Russian side,” he said.

At the Officers House, the hardships have done little to dent support for having troops at the border. Most say that after some rest and relaxation, the soldiers will want to return to the front line.

“They are protecting us,” said Irina Tolkachova, 40, a mother of three whose husband, Sergiy, 40, is with the 79th. “We understand if they weren’t there, all the Russian trucks on the hilltop would be in Odessa and the south of Ukraine.”

Koval, for one, just wants them home again.

“Our boys are heroes,” Koval said. “But I don’t need my son to be a hero. I need him to be alive.”

Alex Ryabchyn contributed to this report.