Creating a demilitarised zone in the Donbas

Wednesday 24 December 2025

President Zelenskyy’s suggestion today that a demilitarised zone in the Donbas might be created by both sides withdrawing an equal distance from the current line of contact has an obvious appeal: it translates an abstract ceasefire into a measurable piece of geography, and it tries to avoid the optics of unilateral retreat by making reciprocity the organising principle. The idea has also been framed alongside proposals for a special economic regime in the east, and as part of a wider draft peace package that would ultimately require domestic approval in Ukraine. 

Yet demilitarised zones are never merely ‘empty space’. In most historical cases they are heavily governed spaces: mapped, verified, policed, supplied and, above all, legitimised by a chain of authority that both sides, however grudgingly, accept. The central question is therefore not only where the lines are drawn, but what the zone is for, who is allowed into it, who arrests whom, which courts have jurisdiction, how violations are investigated, and what happens if one side tries to turn the zone into a platform for renewed coercion.

A helpful starting point is that the “equal distance” logic is not alien to the Donbas. The 2015 Minsk ‘Package of Measures’, endorsed by the UN Security Council, envisaged withdrawal of heavy weapons by both sides “by equal distances” to create specified security zones (of varying depth depending on weapon systems). Minsk failed for many reasons, but its geometry remains instructive: the equal-distance concept is easy to describe and hard to implement unless it sits inside an inspection regime that can survive bad faith.

What history suggests: four workable templates

1. A thin buffer with international patrols: Cyprus

The UN buffer zone in Cyprus is a classic example of a relatively narrow demilitarised strip that is patrolled and monitored, with the political dispute left unresolved. It has endured because the zone is (a) supervised continuously, (b) institutionally ‘owned’ by an external mission and (c) paired with clear rules on what is prohibited inside. 

For the Donbas, a Cyprus-style model would mean a zone that is not necessarily very deep, but is intensively observed and governed, with access points, patrol routes, incident reporting, and a stable, predictable presence that reduces the chance of surprise escalation.

2. A buffer plus limited-force belts: the Golan (UNDOF)

UNDOF on the Golan Heights adds an important refinement: not only is there an “Area of Separation” where the parties’ forces are excluded, but there are also “Areas of Limitation” on either side where the quantity and type of forces and weapons are restricted and monitored. In other words, the buffer is not asked to do all the work by itself; the belts behind it are also regulated. 

Applied to the Donbas, this is arguably the most relevant military-technical precedent. A demilitarised strip without a controlled hinterland risks becoming a tripwire rather than a stabiliser, because the first line behind the zone can be saturated with artillery, drones and air defence.

3. A treaty-defined security map enforced by a non-UN mission: Sinai (MFO)

Sinai demonstrates that, when UN politics blocks a mission, a separate multinational force can still supervise a treaty’s security provisions, including differentiated zones and equipment limits. The existence of the MFO (Multinational Force and Observers) is a reminder that the legal basis matters less than the practical one: both sides must have signed onto the regime and must expect violations to be detected. 

If Russia were to veto a UN mission for the Donbas at the Security Council, a Sinai-type workaround is conceptually available, although it would be politically fraught: the credibility of any mission would depend upon who contributes troops and monitors, and what enforcement powers they actually hold.

4. A “zone of separation” with robust implementation forces: Bosnia (Dayton)

Dayton’s Annex 1-A created an “Agreed Cease-Fire Zone of Separation” extending roughly 2 km on either side of the ceasefire line, with strong rules on weapons in that zone and an external implementation force (IFOR) authorised to ensure compliance. 

The lesson here is not the exact width, but the principle that a demilitarised strip is most stable when the outside force has the authority and capability to act, rather than simply to observe.

Donbas geography: what the land pushes you to do

“Donbas” is not a single natural basin with a neat boundary; it is an industrialised steppe region spread across Donetsk and Luhansk oblasts.  It has some useful geographic features for separating the parties, but they are not continuous, mountain-like barriers. Instead the geography that matters for a demilitarised zone is:

• River corridors and water infrastructure, particularly the Siverskyi Donets system and its tributaries, which are central to water supply and which create identifiable lines on the map. 

  
  

• The northern Donetsk urban chain (Sloviansk–Kramatorsk and connected towns), which sits along river valleys and transport links. Sloviansk, for example, lies on the Kazennyi Torets, a tributary of the Siverskyi Donets, so river geography and urban geography overlap. 

  
  

• The Donets Ridge and upland areas, which do not form a wall but do influence observation, movement and the positioning of infrastructure. 

The practical consequence is that a demilitarised zone designed purely as a constant-width strip around the current line of contact will often cut across towns, industrial sites and waterworks in an administratively nightmarish way. A workable design therefore needs two levels:

1. a default equal-distance withdrawal rule, because it is politically simple and symmetrical

   
   

2. local “engineering adjustments”, because geography and civilians do not respect the purity of geometry

Where could the borders be drawn?

There are three plausible ways to draw a Donbas demilitarised zone while staying faithful to “equal distance” and to the land itself.

Option A: A constant-width strip centred on the current line of contact

This is the purest expression of Zelenskyy’s framing: both sides pull back, say, 10–15 km, creating a 20–30 km band in which regular armed formations and heavy weapons are prohibited, with monitored corridors for civilians and essential services.

Its advantages are obvious: it is easy to explain, easy to verify on paper, and hard to game rhetorically. Its disadvantages are also obvious: it risks bisecting settlements and industrial zones, and it creates a long, thin space that must be policed everywhere at once.

Historically, constant-width strips work best when the surrounding belts are also limited (UNDOF logic), because otherwise the strip becomes a ‘no man’s land’ under permanent overwatch. 

Option B: A strip plus “urban exclusions” to avoid splitting key towns

Under this approach the zone remains centred on the current line of contact, but with negotiated deviations around major population centres and critical infrastructure. The deviations would be designed to keep a town on one side of the boundary of the zone rather than inside it, while preserving the principle that any deviation must be offset elsewhere so that neither side gains net territorial advantage.

In the Donbas context, this matters most in the northern Donetsk conurbation, which is strategically and symbolically central, and which is tied to river and transport geography. 

The key administrative point is that “exclusions” should be rule-governed, not ad hoc. A sensible set of rules rule might be:

• towns above a defined pre-war population threshold are excluded from the zone

• the zone boundary in those areas follows recognisable features (river lines, major roads, rail lines, or municipal boundaries)

• the mission’s mandate includes maintaining access to water, power and transport links that cross the zone

This is the Cyprus approach adapted to an industrial theatre: the map follows lived geography, and the mission’s job includes keeping the practical arteries open.

Option C: A zoned regime organised around waterways and infrastructure

A third approach is to let geography do more of the work. The Donbas is famously constrained by water scarcity and dependency on water infrastructure, and the OSCE has long emphasised how central the Siverskyi Donets basin and associated systems are to civilian life. 

One could imagine a demilitarised zone whose boundaries, in its northern stretches, track river corridors more explicitly, creating a “water-protection and civilian-security belt” where military formations are excluded and critical infrastructure is protected by an international mandate. In the centre and south, where rivers are less continuously helpful as boundaries, the zone would revert to a constant-width design with local adjustments.

This has two benefits:

• it ties the demilitarisation regime to civilian necessities, which makes violations politically costly

  
  

• it provides natural, legible boundaries that can be monitored, fenced in places, and administered through controlled crossing points

The downside is that it risks turning infrastructure protection into a permanent bargaining chip. To prevent this, the regime must specify that infrastructure in and across the zone is operated by civilian entities under international monitoring, not used as leverage by either party.

How would the demilitarisation actually be undertaken?

The mechanics should be familiar from past arrangements, including Minsk’s own conceptual architecture (even if Minsk never held), and from Dayton-style implementation practice.

A workable sequence is:

1. Ceasefire with a detailed, published map annex showing the agreed line from which withdrawals are measured.

2. Phased withdrawal: first heavy weapons and regular formations, then restrictions on other armed actors.

3. Establishment of monitored storage or cantonment areas outside the limited-force belts, with inspection rights and serial-number accounting (this is the unglamorous, essential part that Minsk struggled to achieve consistently). 

4. A standing incident mechanism: a joint commission chaired by the international mission, with rapid investigation teams, published findings where possible, and a ladder of responses.

5. A regulated air and drone regime over the zone. Historical precedents predate drone ubiquity, but the underlying principle still holds: demilitarisation fails if the zone is transparent to one side and opaque to the other. The mandate should include authorised monitoring flights by the mission and prohibitions on unauthorised military flights over the zone.

The hardest issue: who governs the zone?

A demilitarised zone in the Donbas cannot simply be “ungoverned Ukraine”. Somebody must issue documents, run courts, police crime, keep schools open, handle property disputes, and prevent the zone becoming a haven for coercion. There are three governance models, each with a historical analogue.

Model 1: Ukrainian sovereignty, special security regime, internationally monitored policing

Under this model Ukraine’s sovereignty is explicit and continuous, but the zone has a special security statute:

• no regular armed formations inside

• policing carried out by a vetted civilian police service, trained and monitored by an international mission

• an international presence with guaranteed access and verification authority

This resembles the more modest end of buffer-zone practice, but it requires Russia to accept that the zone is not a disguised transfer of political control. That acceptance is not impossible in theory, but it would likely demand reciprocal guarantees about what Ukraine is allowed to base immediately outside the zone, hence the relevance of UNDOF-style limitation belts. 

Model 2: Joint civil administration under international chairmanship

Some reporting around current proposals has referred to joint administration concepts in demilitarised areas. A joint arrangement would typically look like this:

• local municipal services continue day-to-day work

• a civil administration board includes Ukrainian representatives, local representatives, and an international chair with tie-breaking authority

• policing and border control are separated from politics, placed under an international mission or a hybrid body

The advantage is that it offers Russia a face-saving claim that the zone is not simply a Ukrainian security buffer. The disadvantage is that joint administrations can become arenas for sabotage and paralysis, unless the international chair has real executive authority.

Model 3: Transitional international administration (a ‘UNTAES’ analogue)

If the goal is not merely to freeze the conflict but to prepare an eventual political settlement, then the strongest historical precedent is UNTAES in Eastern Slavonia, which combined military supervision of demilitarisation with civilian governance functions for a fixed transitional period. 

A Donbas transitional administration would be politically enormous, but it has conceptual clarity:

• the zone is temporarily governed by an international authority with executive powers

• demilitarisation is supervised as a core task

• return of displaced persons, property restitution, and restoration of services are integrated into the mandate

• at the end of a fixed period, a status process (elections, referendum, or reintegration steps) occurs under monitored conditions

This model is the most administratively coherent, but it is also the most difficult to negotiate, because it requires both Ukraine and Russia to accept an external body with real powers on territory both sides claim.

What the zone’s internal rules would need to look like

Whatever the governance model, the zone’s legal regime must be written as enforceable rules rather than aspirations. The minimum package usually includes:

• Prohibited items and persons: clear definitions of what constitutes a military formation, what weapon categories are excluded, and what security personnel are permitted (typically lightly armed police under strict rules).

• Controlled entry and crossings: designated crossing points, inspection rules, and humanitarian corridors.

• Property and policing: a temporary property claims mechanism, because displacement has been vast and property disputes will be a constant source of disorder; and a policing statute with international monitoring.

• Courts and detention: either Ukrainian courts with special procedures and international observation, or a hybrid chamber for zone-related offences.

• Infrastructure protections: water, power, rail, and industrial safety are treated as protected civilian functions, with international monitoring and emergency repair rights.

This last point is not decorative. In the Donbas, physical infrastructure is a core part of civilian survivability, and it is also an arena in which coercion can be practised indirectly. OSCE’s attention to water constraints underlines why a demilitarised zone that ignores infrastructure will be a zone that bleeds civilians. 

A realistic judgement

A demilitarised zone created by equal withdrawals is feasible in the narrow technical sense: maps can be drawn, distances measured, and rules written. The real tests are political and administrative:

• whether the zone is paired with limitation belts, so that it is not merely a fragile strip under permanent pressure (Golan logic)

• whether the monitoring mission has continuous access and the authority to investigate and report, with some capacity to compel compliance (Bosnia logic)

• whether governance inside the zone is strong enough to prevent criminality, coercion and ‘grey armed’ control, which is the most likely way a demilitarised zone is hollowed out without an obvious tank crossing

If one were to choose amongst the historical precedents, the most credible Donbas design is a hybrid of UNDOF and UNTAES: a demilitarised strip with regulated belts behind it, and a civilian governance regime that is either internationally chaired or internationally administered for a fixed transitional period. 

Finally, geography suggests a sober conclusion. The Donbas does not offer a single majestic natural boundary that can substitute for trust. Rivers and ridges can help draw legible lines, especially in the north where the Siverskyi Donets system and tributaries structure settlements and services, but they cannot do the governing. If a demilitarised zone is to hold, it must be treated not as an empty band on a map, but as a governed corridor whose legitimacy comes from verification, administration and a credible promise that civilians will live better inside it than they did on the front line.