In February 2022, as Russian forces launched their invasion of Ukraine, an unlikely weapon shielded Kyiv, the nation’s capital, from swift defeat: a restored wetland. The attackers advanced from Belarus, which lies to the north of the city, using roads that cut through swamps, peatlands, and waterlogged forests along the banks of the Pripjet and Dnepr rivers.
In their desperation, the Ukrainian army blew holes into a dam on the Irpin River, situated in the northwestern outskirts of the capital, and flooded a large swath of land upstream from where the river meets the massive Kyiv Reservoir. Almost overnight, the planned staging area for Russia’s final assault on Kyiv was turned into a muddy floodplain. The attack began to falter. Images of abandoned Russian tanks mired in the mud circulated globally, earning the Ukrainian army praise for its ingenious use of “hydraulic warfare” or “war-wilding,” as one expert called it.
“The flooding of the Irpin valley became a symbol of how nature can be used to defend against an invader, says Oleksii Vasyliuk, a zoologist with the Ukrainian Academy of Sciences and director of the Ukrainian Nature Conservation Group. To the northeast of Kyiv, nature didn’t even require human intervention. “The landscape there is so rich in peatlands,” Vasyliuk notes, “that many Russian tanks and other armored vehicles simply sank into the ground.” After this setback, Russia abandoned plans to advance into Kyiv and has since focused its ground assault on driers regions in Ukraine’s southeast. Environmentalists have proposed giving the Irpin military honors as the “Hero River.”
“Throughout human history, battles were won or lost because of mountains, bogs, or rivers,” a Ukrainian scientist notes.
Now, scientists from Ukraine, Poland, and Germany are advocating taking these events as an inspiration for a large-scale European “natural defense” strategy. They envision hundreds, even thousands, of miles of restored and protected wetlands and dense, soggy forests along the continent’s eastern borders. Their goal is to address two of Europe’s most pressing challenges at once — the existential threat of a feared larger Russian military escalation in the early 2030s, and advancing key climate neutrality and biodiversity goals.
“Throughout human history, battles were won or lost because of mountains, bogs, or rivers,” says Bohdan Prots, head of the department of landscape and biota diversity at the State Museum of Natural History in Lviv, “so Ukraine and other European countries should remember this and use nature conservation and restoration to their advantage.” Prots has been a vocal supporter of natural defense strategies since doing fieldwork in old-growth forests north of Kyiv when the Russians were amassing troops on the Belarusian side in early 2022. “I wished back then that we had rewilded the whole border area already, as the Russians wouldn’t have considered a ground attack on our capital in the first place,” he says. To support his argument, Prots has compiled a database of Russian tanks that were abandoned or hit after getting stuck in Ukrainian wetlands.
The most ambitious proposals so far were made in April, when prominent wetland scientists Hans Joosten and Franziska Tanneberger, both with the German peatland conservation group Greifswald Mire Centre, and Malte Schneider, managing director of the Berlin-based nature restoration company “aeco,” issued an ecological call to arms. “The Russian war of aggression against Ukraine since 2022 has made it clear that Europe needs to rethink its defense capabilities,” they write. Spending vast sums on conventional arms should be complemented by “innovative, cost-efficient, and synergistic solutions” like rewetting peatlands,” they propose — “a measure that advances Europe’s security as well as its climate and nature conservation efforts.”
Military strategists are taking notice.
“The natural environment in the border areas is an obvious ally of any actions enhancing the elements of the Eastern Shield,” a spokesperson for the Polish Ministry of National Defense, said in a statement, referring to Polish plans to fortify its eastern borders in preparation for Russian aggression. The German army, the Bundeswehr, has made sure it has a say in the nation’s action plan for rewetting large swaths of peatlands as part of its 2045 climate-neutrality target. “Wetlands are an important factor to consider in operational barrier planning,” an army spokesperson says.
The proposal by Joosten, Tanneberger, and Schneider leverages the abundant peatlands of Scandinavia and Central Europe, particularly in the Baltic countries and Polisia, a wetland region spanning parts of Ukraine, Poland, and Belarus. While some of these peatlands remain in their natural state, many were drained in the 20th century as part of initiatives aimed at creating additional farmland. These drained areas have become important sources of greenhouse gas emissions — and easy to cross for humans.
A damaged Russian vehicle mired in wetland in Moshchun, Ukraine, April 2022.
Serhii Mykhalchuk / Global Images Ukraine via Getty Images
The proposal cites a 2016 Belarusian publication that detailed how wet peatlands can bear 75 percent less load from military vehicles than drained areas. “Naturally wet and rewetted peatlands are impassable for tanks, slowing down troop movements and funneling them into more predictable corridors that are easier to defend,” Joosten, Tanneberger, and Schneider say.
They propose a nature-based barrier system comprising three large strips of existing and restored peatlands and wet forests in Ukraine, eastern Poland, the Baltic states, Finland, and Romania, and, as an additional line of defense, newly restored peatlands in eastern Germany. Under their plan, a European Union fund with 250 million to 500 million euros would be created to finance new security infrastructure for an initial area of at least 250,000 acres. Additionally, they suggest generating and selling verified CO2 offset certificates derived from peatland restoration to finance more projects.
In Poland, a group of scientists coordinated by Michał Żmihorski, director of the Mammal Research Institute of the Polish Academy of Sciences, was invited by the military leadership to present a detailed plan for “using the natural environment as a border security measure.”
The German military is concerned that these natural barriers can not only limit the movement of the enemy, but also its own forces.
“In a very good and long meeting with the general in charge of the Eastern Shield in January, we quickly agreed that wetlands and wet forests are the best barriers against invading troops,” Żmihorski says. His institute is located in Białowieża, one of Poland’s prime conservation areas, which is world-famous for its valuable forest habitat that is home to lynx and European bison.
Żmihorski fears that some in the Polish military want the Eastern Shield, their country’s newly designed border with Ukraine, to be a strip of barren land with paved roads, watchtowers, walls, fences and concrete pylons. “The idea that total visibility helps in defense is ill-guided, as walls can be blown up and overrun easily,” he says. “That can’t happen to wetlands and dense forests.” In 2022, the Polish government built an 18-foot-high wall through Białowieża Forest to stop migrants from entering the EU illegally via Belarus. Scientists from Żmihorski’s institute are documenting the damage this is causing to the forest ecosystem. “The wall should not be used as a blueprint for the Eastern Shield,” Żmihorski says.
Instead, the report he coauthored with other Polish experts, details numerous nature-based approaches like leaving dead wood to pile up in forests, abandoning clear-cuts, narrowing forest roads and reducing their numbers, and rewetting peatlands.
Scientists have proposed restoring and protecting peatlands (green) along key European borders (orange) to guard against Russian aggression. Sources: aeco, GRID-Arendal
Yale Environment 360
“We recommend restoring a belt of wetlands along the border,” the experts wrote. Where farmland is needed, they suggest compensation or subsidies for farmers to make up for any losses. “We should stop draining wetlands and forests in our country’s east immediately,” Żmihorski says. As an added benefit, this would help to bring down Poland’s greenhouse gas emissions. When drained peatland dries out, peat disintegrates and turns into CO2. In Poland, this process causes millions of tons of CO2 emissions annually, ranging from a government statistic of 5 million tons per year to researchers’ estimates of 26 million to 35 million tons.
Żmihorski says he is disappointed the government isn’t already implementing the scientists’ recommendations in state-owned forests, but he hopes the military will use its power to make “natural defense” work. The Polish Department of Defense points to a steering group for the development of the Eastern Shield that was formed last December and tasked with finding common ground with conservation experts for the “use of terrain as area-denial zones.” The defense department says it will use engineering solutions where the landscape isn’t suitable for nature-based approaches. “Existing natural resources [will] remain on at least the current level, and actions enhancing them will be supported in a number of locations,” a spokesperson said, adding: “In this instance, environmental and defensive aims overlap.”
Some Polish scientists are wary of these developments. “I am hesitant about the integration of border security and nature conservation, as the security apparatus already weaponizes landscapes against people on the move and may further militarize and exclude the public from such natural areas,” says Katarzyna Nowak, a biologist at the Mammal Research Institute who has led the study of the ecological damage done by the border wall with Belarus. “This won’t bode well for human connection to borderland landscapes,” she says.
The German Ministry of Defense has very different concerns: Natural barriers cannot only limit the movement of the enemy, but also of its own forces, a spokesperson said: “The rewetting of wetlands can be both an advantage and a disadvantage for your own operations.” While broadly supportive of peatland restoration, German defense planners want to have a say on a case-by-case basis.
The strategic use of peatlands, marshes, and floodplains in war has a long history. In the early 19th century, the famous Prussian major-general and strategist Carl von Clausewitz dedicated a whole chapter in his seminal work On War to the “peculiarities of morasses.”
Military historians cite the “Dutch Waterline” as an example of the active creation of wetlands for warfare. In the 16th and 17th century, “strategic flooding” by destroying dykes was used by the Dutch to fight off the Spanish, then French invaders. This led to the development of sophisticated methods to use canals and locks for defense in the 18th century. According to environmental historian Adriaan de Kraker, the Netherlands used “strategic flooding” several times in both the First and Second World Wars.
Ukraine’s Irpin valley is still soggy and under military control, but landowners there would need to consent to future nature protection.
Olga Denyshchyk, a Ukrainian ecologist and project coordinator at the Michael Succow Foundation in Greifswald, Germany, says that wetlands were an important factor in World War I, when “Austrian troops were literally bogged down in Polisia,” and in World War II, when Soviet scientists helped to determine that the best timing for large-scale attacks against the German invaders was in late fall, when peatlands start to freeze over, and spring, when they thaw.
Denyshchyk is dismayed, however, that today peatland science and understanding of the military importance of wetlands has all but vanished in her home country. “Academia, politics, the military, and the general population have no awareness of the role and importance of peatlands in today’s Ukraine,” she says. Denyshchyk sees this as one reason why natural defense strategies haven’t gained widespread support and traction in Ukraine despite the iconic success in the Irpin river valley. She has contacted the Ukrainian Ministry of Defense to try to make the case that a comprehensive natural defense strategy is needed, but so far without success.
Vasyliuk, who is director of the Ukrainian Nature Conservation Group, hasn’t received a reply either after writing to the Defense Ministry with proposals for a Ukrainian natural defense strategy. “In a way I understand this, because our defense officials are faced with constant air raids on our cities and villages, and they don’t even find the time to deal with issues they deem crucial,” he says. As another attack from the north isn’t imminent, expanding wetland barriers is not seen as a priority.
Destroyed Russian vehicles in flooded parts of Moshchun, Ukraine, in April 2022
Vasyliuk and Denyshchyk cite competition for land as the main reason why Ukraine has not yet fully endorsed natural defense methods, and why proposals to turn the Irpin valley into a protected wetland have so far fallen flat. “The Irpin valley is still soggy and under military control right now, but landowners in the area would need to consent to future nature protection,’’ Vasyliuk says, ‘’and they have made clear that they want to use it for building homes and farming, as this promises the highest return.”
Denyshchyk warns that mining for amber, a valuable fossil resin found in peatland regions and sought after for jewelry, poses another threat. On a fact-finding mission in the Ukrainian peatland regions bordering Belarus, she met local officials supportive of rewilding — as long as residents are provided with income and jobs. “People have lost so much in this war, they cling to their existing assets and their tested ways to make a living — it will need a lot of convincing for them to tap into carbon certificates or paludiculture,” a new set of methods for wetland farming, Denyshchyk says. But a number of paludiculture and rewilding projects are already underway in border areas, creating models for a future broader strategy, she notes.
Both Ukrainian scientists are optimistic that the war will end with a Russian retreat and that Ukraine’s decision-makers will then be open to new ideas. “Once we join the European Union, ” Vasyliuk says, “many of our wetlands will enjoy enhanced protection as part of the EU’s Natura 2000 network, and the military will have time to make strategic decisions about natural barriers in the border region it controls.”
