The Berlin talks and a US security guarantee for Ukraine

The recent talks in Berlin between United States envoys and European leaders have placed the most contentious question in the peace process back where it belongs: not on maps, but on credibility. Territory can be written into an agreement; deterrence has to be lived. In Berlin, Washington signalled a willingness to contemplate NATO-style assurances for Ukraine, while European capitals sketched a complementary architecture built around a European-led multinational force, continued Ukrainian military mass and a monitoring mechanism designed to make cheating visible early enough to matter. 

What, then, is the substance of “US security guarantees” in this setting, and what are they actually for?

Guarantees as a substitute for NATO membership

A central idea emerging from the Berlin discussions is an “Article 5-like” guarantee for Ukraine as an alternative to formal NATO accession. In plain language, this is an attempt to separate two things that Moscow has sought to fuse: the promise that Ukraine will be defended if attacked again, and the institutional step of bringing her into the Alliance. Ukraine, for her part, has reportedly signalled a readiness to set aside the NATO membership bid if she receives guarantees robust enough to make renewed Russian aggression irrational. 

The logic is straightforward. The war has demonstrated that Ukraine can fight, innovate and absorb punishment, but deterrence fails when the aggressor believes that escalation will not trigger intervention by the strongest outside power. An Article 5-like commitment is therefore aimed less at daily battlefield advantage than at shaping Russian expectations the morning after any ceasefire is signed.

What Europe put on the table: a force, a ceiling, and a tripwire

European leaders emerging from Berlin endorsed a package that, according to the joint messaging reported publicly, includes three core elements.

First, a European-led multinational force operating in support of Ukraine, with tasks that include helping rebuild Ukrainian forces and contributing to the security of Ukraine’s skies and seas. 

Second, an emphasis on Ukraine sustaining a very large standing force, framed at roughly 800,000 personnel, so that the post-war baseline is not demobilisation but a hardened posture. 

Third, a US-led ceasefire monitoring mechanism intended to detect and respond to future threats, which matters because deterrence is partly a technical problem: if violations are ambiguous, response becomes political, and politics is slow. 

Put together, these elements suggest a European “presence guarantee” married to an American “consequence guarantee”. Europe supplies proximity and persistence; America supplies escalatory authority.

What the United States is actually offering, and why wording matters

Reuters reporting from Berlin frames the American offer as “NATO-style security guarantees”, and European leaders have treated it as a significant shift, with Poland’s Prime Minister Donald Tusk describing an American posture that would make Moscow expect a military response if Russia attacked again. That phrasing is politically explosive because it implies more than weapons deliveries or training missions. It implies a conditional promise of US force.

Yet there are several gradations hidden inside the word “guarantee”:

1. Political guarantee: a declaratory commitment, perhaps jointly issued, promising a response but leaving the form of response ambiguous.

   
   

2. Legal guarantee: a treaty or treaty-like instrument creating an obligation under US law, typically more durable but harder to secure domestically.

   
   

3. Operational guarantee: concrete measures that make any promise easier to execute, such as pre-positioned equipment, integrated command arrangements, standing plans, intelligence links and air and missile defence integration.

   
   

4. Economic guarantee: automatic sanctions snapback, asset seizures, or reconstruction and financing mechanisms that punish renewed aggression and reward compliance.

Berlin appears to be about combining these layers. European statements refer not only to military measures but also to economic recovery support as part of the same post-ceasefire framework. 

The key point is that deterrence is produced by capability plus intent plus speed. A guarantee that requires a fresh political debate in Washington every time Russia probes the line is, in practice, a weak guarantee, no matter how eloquent her phrasing.

The hard bargain hiding behind the guarantees

Security guarantees did not emerge in Berlin as a gift. They appeared as a price, and the bill is being presented in the language of territorial concessions. Reuters reports that US negotiators conveyed that any agreement with Russia would require Ukrainian withdrawal from some part of the Donetsk region currently under Ukrainian control, and that significant differences remain over territorial issues even as talks continue. 

This is the structural tension at the heart of the Berlin process:

• Ukraine and Europe want guarantees first, then any discussion of territorial outcomes.

• Washington appears to be testing whether stronger guarantees can unlock Ukrainian flexibility on territory.

• Moscow will seek to pocket territory while diluting the guarantee into something symbolic.

Keir Starmer’s intervention in this process captures the European fear: agreements without enforcement become pauses, and Russia has historically exploited weak commitments. In that sense, guarantees are not an “add-on” to a settlement. They are the settlement’s engine.

Why America matters even if Europe provides the force

A European-led multinational force, even a serious one, confronts two problems.

First, escalation dominance. If Russia chooses to test a ceasefire with an operation too large for Europe to handle cleanly but too small to look like a new full-scale invasion, Moscow will try to split the coalition. An American backstop is meant to close that gap.

Second, coherence. European forces can deploy, but integrated air and missile defence, intelligence fusion and long-range strike planning are areas where American capabilities and planning culture often provide the backbone. The Berlin discussions explicitly linked a European-led force to US support and to a US-led monitoring element, which is an implicit recognition that Europe alone cannot create a guarantee Moscow will fear. 

The credibility problem in Washington

Even if the American offer is real, she will be scrutinised for durability. A guarantee that can be reversed by the next administration, or weakened by Congressional obstruction, is a guarantee Moscow can wait out. That is why legal form matters, but also why operational form matters more. Pre-positioning, integrated planning, and automatic imposition of sanctions and military aid can make a promise harder to unwind in practice, even if politics shifts.

Berlin also illustrates another reality: the United States can offer a guarantee in words quickly, but she cannot manufacture trust quickly. Trust is accumulated through consistent behaviour over time.

What would count as a “robust” US guarantee in practical terms?

If one tries to translate the Berlin mood into a concrete, credible structure, the most plausible “robust guarantee” is a layered system:

• A European-led multinational force inside Ukraine performing stabilisation, training, airspace and maritime support tasks. 

• A standing Ukrainian force kept large enough to deter opportunistic offensives, framed by European leaders at around 800,000. 

• A US-led monitoring and verification mechanism that produces fast, public, technically grounded attribution of violations. 

• An American commitment, clearly phrased, that a renewed Russian attack triggers specified actions, ideally including military measures, not merely further aid.

• Automatic economic consequences, so that Russia faces immediate costs without weeks of allied argument.

This combination is not NATO membership in all but name, but it is an attempt to achieve NATO’s central effect: to make the aggressor believe that another war will be worse than the last one.

The strategic significance of Berlin

Berlin matters less because it “solves” the peace process and more because it begins to answer the only question that can stabilise a post-ceasefire Ukraine: who, precisely, will fight if Russia returns?

If the United States truly intends to put a military response on the table, as European leaders have suggested they heard in Berlin, the entire bargaining landscape shifts. If however the guarantee slides back into ambiguity, the talks risk producing a document that looks like peace but functions like an intermission.

The most important feature of any American guarantee is not how it is described, but whether it is designed to be automatic, fast and politically survivable. Berlin suggests the negotiators have begun to grapple with that reality. Whether they can preserve it through the inevitable territorial bargaining is the next test.