A soldier of Artan, a special unit of Ukraine's Defense Intelligence, known by the callsign Derun, described the fighting during important Ukraine's Operation Vivaldi, according to Novyny.Live. He says the hardest part of Ukraine's counteroffensive in the northern part of Donetsk Oblast is prying Russian troops out of positions they have fortified so well that they see every approach coming.

Vivaldi is bigger than any one assault. It is the counteroffensive that the Third Army Corps is running near Lyman. The Institute for the Study of War says it has disrupted Russia's plan to encircle the fortified "Fortress Belt" of Donetsk cities, as the corps says its first phase cleared 75 square kilometers of Russian infiltrators and de-occupied another 10.

Dug-in Russians see every approach

The problem is Russia's preparation, when "the enemy has made his positions very well fortified," Derun said.

"The hardest is to knock him out of there, because when a position is competently prepared, they see everything," he explained.

A well-sited position lets the defenders watch the open ground an assault group has to cross, spot the attackers early, and fight them at a distance, which is the worst way for the attacker to come.

A lapse opens the way in

When Russian troops stop watching the approaches to their position, the assault group can close the gap unseen, Derun said.

"When Russian troops are distracted, it can play into our hands: we can approach under cover, when he does not see us, and work him from close range," he added.

Once the attackers are in close, he added, the defenders can start to panic and make mistakes.

Vivaldi runs to four seasons

Artan fought as part of a larger force. Alongside the Third Army Corps' own brigades, the operation drew in Ukraine's Special Operations Forces, the border guard, and the military-intelligence unit, all under a single tactical command, and it ran for months under an information blackout before the corps disclosed it.

The corps commander, Andrii Biletskyi, said the phase revealed so far is only the first of four, naming the operation for Vivaldi's Four Seasons.

"This is only the first," he said, promising more.