On September 4, 2025, in Paris, Emmanuel Macron gathered a "coalition of the willing." He stated that 26 countries are ready to contribute to a reassurance force for Ukraine. This force will be deployable after a ceasefire in Ukraine and will operate away from the front line. What is the purpose of this announcement, who decides, where and when would it apply, and how would it be managed? An analysis of the stakes, American support, and areas of uncertainty.
What was decided in Paris on September 4, 2025
Following a meeting of the "coalition of the willing" at the Élysée, Emmanuel Macron assures that 26 countries are ready. These countries will contribute to a "reassurance force" for Ukraine. This force will be present on the ground, at sea, or in the air, and deployable after a ceasefire in Ukraine. Additionally, it will operate away from the front line. The political objective is clear: to raise the cost of a new aggression and secure the "post-war" period. The operational details remain deliberately vague, with the Élysée mentioning "robust" guarantees. Furthermore, a framework of guarantees for Ukraine is being finalized with Washington.
In this context, Volodymyr Zelensky welcomes a "concrete" advancement. The partners also discuss a possible strengthening of sanctions if Moscow refuses negotiations. Steve Witkoff, envoy of American President Donald Trump, is present in Paris, and a videoconference with the White House follows the meeting, signaling an assumed transatlantic backing.
A claimed strategic ambiguity
Neither deployment zones nor rules of engagement are publicly detailed. This strategic ambiguity aims to reassure Kyiv and deter Moscow. It avoids providing leverage to Russian propaganda while preventing capitals from making hasty promises. It is effective in the short term for displaying European leadership but shifts the burden of proof: tomorrow, the announcement will need to be transformed into concrete arrangements such as status of forces agreements, command chains, Ukraine’s air defense, logistical support, rotations, and funding.
This method involves a deferred political cost. The more general the statement remains, the more parliaments will demand guarantees when deploying European troops in Ukraine. The equation is known: military coherence, legal legitimacy, and public support must advance together.
European autonomy under an American umbrella
The Parisian staging outlines a Europe taking the initiative that locks in behind an American safety net. The United States is expected to provide intelligence, air defense, and financial sanctions. Politically, it is a gamble of relative autonomy: Europe decides, America endorses, Ukraine arbitrates.
The presence of Steve Witkoff and the call with Donald Trump anchor this co-production. Without American backing, the credibility of deterrence for Ukraine, particularly aerospace and cyber, would remain incomplete. But the more visible the transatlantic bond, the more the promise of "strategic autonomy" will need to convince. It must prove that it is not just a slogan.
"It is not up to Russia to decide": a normative marker
NATO Secretary General Mark Rutte sets the guideline. He asserts that "it is not up to Russia to decide". This concerns the deployment of Western troops if Kyiv requests it and within the framework of a ceasefire. The message is normative as well as military: no veto for Moscow on a post-conflict security arrangement. The public argument emphasizes: it is about preparing peace through credible deterrence for Ukraine, not escalating the war.
This doctrine will, however, need to withstand two tests. On one hand, perception tests orchestrated by Moscow will pose a challenge. On the other hand, European public fatigue could arise. This will happen if the "interregnum" between ceasefire and peace agreement drags on.
Fault lines: Berlin, Rome, and the parliamentary mechanics
Behind the display of unity, the granularity of commitments diverges. Some governments say they are ready to deploy, while others prioritize training, cyber defense, demining, financial support, or maintenance. Berlin increases support but delays on troop deployment, referring to conditions: American participation, engaged negotiations, Bundestag approval. Rome and other capitals navigate between European solidarity and internal constraints.
This parliamentary mechanics will be decisive at the engagement moment. Executives have gained time through the announcement, but they will have to pay upfront during votes and in budgets. If Washington slows down, the European domino may waver.
Coalition of the willing for Ukraine’s security
The choice of a security coalition for Ukraine (ad hoc), outside NATO and EU frameworks, presents several advantages. Indeed, it allows avoiding the unanimity required in these organizations. Moreover, this approach helps accelerate decision-making processes. But it weakens the legal clarity. The basis relies on Ukraine’s invitation, which is sufficient under international law for military assistance. Additionally, this invitation will be complemented by bilateral agreements and status of forces agreements (SOFA). Advantage: flexibility. Risk: heterogeneous legal regimes and complex command chains.
To remain credible, the coalition will need to industrialize its promise: joint planning, interoperability, integrated air protection, common logistics, funding framework, and unit rotation. Without this, deterrence will dissolve into rhetoric.
A political narrative: reframing the European debate
Internally and externally, the Macron camp seeks to re-hierarchize the debate. Naming the military presence "reassurance" rather than "intervention" aims to depolarize. In France, the executive launches a challenge to the opposition: on the right, it is about denouncing an adventure. However, this must be done without appearing to renounce European security. As for the radical left, it must criticize the coalition while assuming the aid to an attacked country. On the European stage, Paris advocates for a "robust peace" that conditions the negotiation, rather than the reverse.
This grammar is consistent with the idea of a "armed peace": deterrence, reassurance, sanctions. It requires holding together the promise made to Kyiv and the control of the risk of escalation.
Calculated risks
Risk of hollow promise: if the ceasefire is delayed, the force remains virtual, credibility erodes, public opinion grows impatient.
Risk of engagement: when it comes to actually deploying European troops in Ukraine, parliaments and budgets may slow down. The electoral period in several countries will weigh on the execution window.
Narrative risk: Moscow will seek to requalify the arrangement as "foreign occupation", testing European resilience over time. Conversely, announcing nothing would have confirmed the image of Western fatigue. Paris chooses the threshold effect: signaling today what would happen the day after peace.
What does the "reassurance force" for Ukraine cover?
The term is not a fixed legal concept. It refers to a mix of defensive and stabilization missions in Ukraine:
- Multilayered air defense (sensors, interceptors, electronic warfare) to sanctuarize the Ukrainian airspace post-ceasefire.
- Maritime security in the Black Sea: dredging, escorts, commercial corridors, ISR surveillance.
- Demining and counter-IED on civilian routes and critical sites.
- Protection of infrastructure (energy, water, health, rail), with CIED teams, cyber and civil protection.
- Regeneration of Ukrainian forces: maintenance, MCO, advanced training, ammunition supply
- Limited deterrent presence, away from the front line, on sites identified by Kyiv, with strictly defensive rules of engagement.
These options require tight integration with the Ukrainian general staff, common deconfliction procedures, a joint threat assessment cell, and a politico-military dashboard to adapt the arrangement.
References and precedents: models not to be copied
Historical references abound but none exactly overlaps. NATO missions in the Balkans (IFOR/SFOR, KFOR) were based on Security Council resolutions and a stabilized multilateral framework. The EU’s civilian missions (e.g., EUBAM, EUMM) illustrate post-conflict support, but with different mandates and means. The future Ukrainian scheme would be unprecedented: a coalition of states invited by Kyiv, linked to political-financial guarantees and a prominent American role.
Consequence: more agility, less clarity. The price of flexibility will be a clear governance, accepted by Kyiv, and a public mandate understandable to the public.
What can be said today
Politically, Emmanuel Macron takes the lead by proposing an architecture of armed peace: deterrence, reassurance, sanctions, with an American bond. The success hinges on two pivots: the operational orchestration (mandate, command, rules of engagement) and the transatlantic durability. At this stage, the "reassurance force" serves more as a negotiation tool than a deployment plan. Indeed, it raises the cost of resuming hostilities and opens a door to a secured peace.
Figures and references
- 26 contributing countries announced in Paris, September 4, 2025.
- 35 delegations involved in the coalition of the willing (in-person and virtual).
- 60% of the weapons used by Ukraine would be produced in Ukraine, according to Emmanuel Macron. With the help of allies, it is a priority to intensify this effort.
- Additional sanctions under consideration if Moscow refuses peace talks.
Assessment: an armed peace under conditions
A promise of secured peace is only as good as its ability to become procedures, means, and mandates. The coalition of the willing has set the course, and now it must build the map. Without a clear command, reassurance will remain just a word. With robust governance and a committed transatlantic backing, it can change the dynamics of the aftermath of the war.