How Ukraine is revamping frontline fortifications to stem Russian advances

KYIV — Russia’s changing attack tactics are forcing Ukraine to adapt by making shorter defense lines and building low-rise strongpoints less visible to drones swarming the skies.

But the revamp is undermined by a chaotic approach to fortifying front lines, with very different approaches being used depending on local commanders. Tougher defense positions are also made much less effective by Ukraine’s chronic shortage of combat troops.

The change in fortification strategy is being driven by Russia dropping large formation attacks supported by armored vehicles in favor of much smaller units backed by drones, Ukrainian Defense Minister Rustem Umerov said last week.

Ukraine is responding by building fortifications for ever smaller units — from battalions of about 500 troops to companies of about 100, and now for platoons of 20 to 50 soldiers.

“Now we see that the most effective position is a maximum of one detachment. And these are mainly groups of trenches, even so-called foxholes, which make it impossible for the enemy to use strike drones. After all, now a drone, especially on fiber optics, can penetrate any hole,” Ukrainian Army Commander in Chief Oleksandr Syrskyi told journalists in Kyiv at the end of June.

Previously, strong points used extensive trench networks from 2 to 5 kilometers in length. The new system uses smaller strongpoints with trench networks 60 to 70 meters long and equipped with mandatory anti-drone cover.  “These are harder to detect and are effective in carrying out tasks of defense, deterrence, and delivering firepower, including against FPV drones,” Umerov said.

Behind that frontline defense, Ukraine is continuing to build two additional lines that include concrete tetrahedrons, also called dragon’s teeth, to hold off armored vehicles, minefields, foxholes, wooden and concrete trenches, anti-drone covers and nets.

“Fortification is not just about concrete and trenches — it is an adaptive engineering system that takes the enemy’s tactics into account and always serves one purpose: protecting our warriors. We monitor the process daily and reinforce the areas where it’s needed most,” Umerov said.

Earlier, fortifications were often built in open terrain to block Russian attacks using large numbers of armored vehicles. Now, they are built around forest belts, which have better camouflage.

Who builds what

The top command insists the military is doing a good job of building fortifications. The vast majority of assigned plans were completed last year and over half of those planned for this year are already done, Umerov said.

But the view from the front lines is a lot more critical, according to analysts and soldiers who spoke to POLITICO.

In Dnipro, a city in central Ukraine where there’s synergy between the military, local governments and other bodies, acting together to help with money, tools and resources, three lines of defense were built solidly and rapidly to hold back Russia’s push from the Donetsk region.

But the situation is a lot patchier in northeastern Ukraine where Russia is now staging a major offensive.

“What is happening in Sumy and Kharkiv regions is a mess. Hardly anybody knows who is responsible for what, and who is supposed to control the process,” said Roman Pohorilyi, co-founder of DeepState, a Ukrainian OSINT group that has created an online map of Russia’s war against Ukraine. He added that the latest Russian offensive has pushed Ukrainian authorities finally to speed up construction.  

“We always wait until the very last moment,” he said.

He also criticized the county’s haphazard approach to fortifying front lines in the crucial zone around the northeastern region of Sumy.

“In Sumy’s Yunakivka village, for example, we saw mountains of dragon’s teeth just left there. In some places, there are trenches, but then nothing in a forest area, where they should be, and then trenches again. I would slap the hands of those responsible for this approach,” Pohorilyi said.

The Ukrainian Defense Ministry has oversight of all fortifications, but several different entities are responsible for building and maintaining them, depending on the defense line: the Armed Forces of Ukraine, the State Special Transport Service of the Defense Ministry, and local military and civilian administrations.

Ukrainian Prime Minister Denys Shmyhal said in January that last year the government spent 46.2 billion hryvnia (€930 million) to build 3,000 defensive points “in threatening directions and in places where active hostilities are not currently taking place.”

The most dangerous work is done by combat troops.

“Ukrainian servicemen still have to dig the first line of trenches with shovels and during active fighting,” Syrskyi said.

Troop shortage

However, any kind of fortified structure is only effective if it’s occupied by a sufficient number of troops, Syrskyi said. Despite mobilization efforts, Kyiv is still outnumbered on the 1,200-km front line by Russia.

“If there are no servicemen in the fortification or their number is insufficient — for example, when a normal strongpoint is built, but two or three soldiers remain in it — of course, this fortification does not play its role,” Syrskyi said.

Russian soldiers are searching for weak spots in Ukraine’s defenses, according to two soldiers, who spoke to POLITICO on condition of anonymity to be able to talk freely.

 “It all depends on the commander. If he orders to dig and mine, the area will be solidly fortified. If [Russians] see your unit dug in well, they attack your neighboring units,” one soldier said.

Pohorilyi confirmed the Russian technique.

“Russians push everywhere, probe for weak and problematic places, they know all of them. And as soon as they find these places, they immediately concentrate their resources and troops there and start piercing,” he said. “And that’s when our defenses start collapsing, unfortunately.”

Disgruntled troops

Soldiers also complain that the military is not properly using battlefield gains to build trenches and other barriers to stop Russian counterattacks.

Ukrainian soldiers spent six months inside Russia’s Kursk region holding off more than 60,000 Russian troops, preventing them from advancing into the Sumy region. They argue they won plenty of time for authorities to construct proper fortifications in the border zone.

“We gave time to prepare the border area for the Russian attack. But they hardly used it with 100 percent efficiency. Protective nets from FPV drones over the main supply roads began to be installed only in January, while they were already under regular Russian drone attacks,” said Ukrainian soldier Artem Kariakin.

“As a result, the route, which from August to December 2024 could be completely and safely covered with nets, was turned into a road of life, along which our weapons systems could pass without damage with a 30 to 70 percent chance not in our favor,” Kariakin added.

He said that local authorities and military units only started digging dugouts in the border area and installing the first dragon’s teeth once Ukrainian forces were retreating from Kursk.

“As a result, by the time many dugouts were finished, the Russians were already much closer, and many positions lost their relevance. I believe that the people responsible for the fortifications lost a huge amount of time and ultimately failed their task. The work was carried out, but with great and extremely illogical delays,” Kariakin said.

Only in June, Russian troops occupied 500 square kilometers of Ukrainian land, DeepState reported, the fastest pace of advance in many months.