Britain and France will jointly lead Exercise Koalicja from 9 to 22 November 2026, involving 2,800 personnel in preparations for a possible postwar mission in Ukraine, the UK Ministry of Defence announced on 3 November. The exercise centres on Poland, with a separate maritime component organised from Istanbul (UK Ministry of Defence). The ministry calls Koalicja the first major exercise of Multinational Force Ukraine, or MNF-U, the military component of the Coalition of the Willing. That description identifies the current formation and rehearsal, while the July Polish announcement establishes that planning for a European reassurance mission and exercises in Poland was already public well before the November dates were released.
The ministry lists 11 participating countries: Belgium, Estonia, France, Germany, Lithuania, the Netherlands, Poland, Spain, Sweden, Turkiye and the United Kingdom. Although BBC reporting carried by AOL referred to 12 European nations, the official named list supports 11; the ministry's personnel figure includes land, air and maritime elements.
A larger rehearsal of an existing plan
The concept predates this announcement: Poland's prime minister's office said in July that British and French forces would rehearse in Poland during the autumn. UATV also reported Deputy Defence Minister Pawel Bejda's expectation that around 1,500 British and French troops would arrive in September to practise movement of personnel and equipment.
Compared with those earlier published plans, the November announcement sets out a larger total and a broader named coalition, with air and maritime activity alongside land movements. The earlier UATV report described an expected deployment, not a completed exercise, so it does not by itself establish that a separate September iteration actually took place.
Moving, protecting and sustaining the force
The UK ministry says the rehearsal will test movement, protection and supply of a force intended to help rebuild Ukraine's armed forces after fighting ends. Its programme includes command-and-control arrangements and integrating different national components, making the exercise a practical test of whether participating units can operate together (UK Ministry of Defence).
Britain will provide about 300 personnel, including troops from 7 Brigade, plus RAF Typhoons and a Voyager tanker, according to the ministry. The same announcement says aircraft will simulate reassurance of reopened commercial airspace, while Turkish forces in Istanbul test maritime arrangements for mine clearance supporting access to Ukrainian ports (UK Ministry of Defence).
An exercise is not a deployment decision
The Associated Press reported that the proposed force would deploy only after a ceasefire and would not be a NATO operation or a ceasefire-monitoring mission. The agency also described unresolved questions over American support and Russia's opposition, which remain obstacles to turning military preparations into an agreed mission on Ukrainian territory (Associated Press).
The UK announcement provides no final deployment date, binding mandate, complete rules of engagement or eventual force size, while BBC reporting says officials could not specify its final shape. The 2,800-person rehearsal therefore measures the scale of this exercise; it is not an announced commitment to send the same force into Ukraine, and the cited reports establish no concluded peace agreement (UK Ministry of Defence).