How landscapes are becoming Europe’s new line of defence

While tanks, drones and missiles dominate discussions everywhere, Brussels and several European capitals are turning their attention to something long regarded purely as a conservation issue: landscapes. Ancient forests, peatlands, floodplains and slow-moving rivers could hold up an invading army while also protecting the climate and biodiversity.

When landscape becomes a line of defence

For a long time, European defence policy meant more weapons, stronger alliances and better technology. A further component is now being considered. Experts and politicians want to restore natural landscapes deliberately so that, in an emergency, they become obstacles for hostile forces.

“The idea: a tank often stands less chance against knee-deep mud than against concrete.”

The European Commission is advancing this issue through its Nature Restoration Regulation. The law is primarily intended to revive damaged ecosystems, covering at least 20 per cent by 2030. Yet internal documents and specialist circles are now looking beyond that aim: selected border areas could intentionally be made more “unfriendly” to heavy military equipment.

The key elements include:

• restored floodplains and river lowlands
• re-wetted peatlands and wetlands
• dense, mature forests with difficult ground conditions

The reasoning is straightforward but effective: the more water a landscape holds in its soil and the more convoluted its terrain, the more slowly an army can advance. This makes surprise attacks harder and gives the defending country time - often the decisive factor in modern warfare.

The lesson from Ukraine: a river slows an offensive

The opening phase of Russia’s 2022 invasion of Ukraine demonstrated just how greatly terrain can shape a military campaign. Russian forces intended to move swiftly and directly towards Kyiv. Under intense time pressure, Ukraine’s leadership took a drastic decision.

A dam on the River Irpin, a tributary of the Dnipro, was opened or destroyed. The valley and its fields flooded within a short period. Farmland turned into an extensive marsh. Light vehicles could still get through, but heavy tank columns and supply lorries faced a nightmare.

Satellite imagery showed that several square kilometres were underwater. Improvised lakes cut across access roads towards the capital. Russian units had to divert, overloaded alternative routes and lost days. What had been planned as a rapid thrust became a slow, error-prone advance.

“The artificially flooded landscape outside Kyiv is now seen as an example of how nature can become a tactical weapon - without high-tech, using only water and topography.”

The vast peatland areas in northern Ukraine also played a part. Their softened ground is notorious in spring. Even modern tracked vehicles can sometimes sink up to their hulls there. Historically, military planners have avoided such areas, because a stuck tank is more valuable than a destroyed one: it blocks routes and ties up resources.

Wetlands as a natural tank barrier

Peatlands, marshes and floodplains have particular physical properties. Their soils contain exceptionally high levels of water and have little load-bearing capacity. Unpleasant for people in boots, they can be highly dangerous for 60-tonne tanks followed by supply lorries.

Military logistics depend on reliable routes. Fuel, ammunition and spare parts move forwards in long convoys. A network of wetlands forces these columns into a small number of dry corridors. Such points are easier to monitor and, if necessary, defend.

Research teams working for European think tanks are already outlining potential chains of restored areas along the EU’s eastern edge. Their premise is that, over hundreds of kilometres, a kind of “green defensive barrier” could emerge - slowing heavy equipment while retaining water and safeguarding habitats.

This is not about creating new marshes in every border community, but about positioning areas intelligently to create bottlenecks. Typical measures include:

Why mature forests are suddenly of interest to generals

Dense, long-established forests are also beginning to feature in security-policy assessments. In Poland, for instance, the new government halted timber extraction in ten particularly valuable mature forest stands at the beginning of 2024. Officially, the measure concerns nature and climate protection - although the strategic position of some areas also plays a role in the background.

Mature forests are hard to read. There is thick undergrowth, abundant deadwood and limited visibility. Drone imagery is less effective, infrared reconnaissance becomes more difficult and vehicles move more slowly. Anyone seeking to travel quickly through such terrain needs light troops who know the area, not endless rows of tanks.

The best-known example is the Białowieża Forest on the border between Poland and Belarus. It is regarded as the last substantial remnant of a primeval European lowland forest. Alongside European bison, lynx and wolves, it contains ancient giant trees. From a military perspective, the area is unpredictable terrain that concentrates attacks into narrow spaces and makes them risky.

“Intact forests do not merely provide shade and habitats - they form natural buffer zones that no vehicle can ‘simply break through’.”

Forests also stabilise soils, retain water and affect the microclimate. During hot summers they cool entire regions, while in periods of heavy rain they slow flash flooding. All of this strengthens a region’s resilience - not only against armies, but also against weather extremes.

Climate, security and water: shared ground

What stands out is the degree to which climate, water and security policy now overlap. Without water there is no agriculture, and without reliable supplies there is no domestic stability - that is the sober calculation made by many governments. Reservoirs, canals and dams now rank high among potential targets in military scenarios.

Wetlands and floodplains perform a dual function here: they buffer floods, retain water for dry periods and at the same time make critical infrastructure harder to hit because water is spread across large areas. Allowing a river to overflow across its floodplain prevents concentrated destruction at a single location.

For citizens, these plans may initially sound abstract. In daily life, they are often reflected in smaller projects:

• a dyke moved back so that meadows behind it can flood again
• a stream released from its concrete channel and allowed to branch out
• a forestry track that is no longer upgraded for heavy vehicles

In an emergency, such measures lengthen an attacker’s route; under normal circumstances, they create new local recreational spaces, cleaner air and greater biodiversity.

What the shift could mean for border regions

People living in border areas are often the first to notice when strategies change. When arable fields become floodplains or timber harvesting stops in particular woodland areas, livelihoods and traditions are affected. Specialists therefore warn against imposing security considerations on land users from above.

At the same time, rural regions in particular could benefit over the longer term. Restoration projects bring funding, tourism and research institutions. Farmers receive payments for more extensive land management, while forestry businesses focus more on woodland care than timber extraction. One thing is certain: anyone reassessing landscape as a strategic factor must also discuss fair compensation models.

One aspect remains underestimated in many debates: the psychological effect. Attackers who know that they will face not only hostile soldiers but also difficult terrain make different calculations. Even the prospect of manoeuvring columns through a fragmented mosaic of river branches, marshes and forest islands can slow military planning.

For Europe, this represents a gradual yet far-reaching change of direction. Landscapes are no longer viewed simply as scenery to be protected because it is beautiful or shelters rare species. They are becoming an active part of the security architecture - quiet, gradual and unspectacular, but potentially enormously effective in an emergency.