Winter in Ukraine is injecting further uncertainty into an already volatile conflict. Concerns are increasing about the strong risk of a humanitarian crisis in the south-eastern separatist-held areas of Donetsk and Luhansk. The separatists have a rudimentary administrative structure, few competent administrators, ill-trained militias and little in the way of a long-term strategy. They will be hard pressed to survive the winter without major Russian aid – financial, humanitarian or military. Ukraine, meanwhile, is dragging its feet on implementing reforms to address its manifold economic problems. Both Kyiv and the separatists are under pressure from their war lobbies. The near-term risk of further hostilities is high. There is an urgent need to halt the conflict, separate the troops, deploy substantially larger numbers of international monitors across the warzone and the Russian-Ukrainian border, as well as take immediate steps to assist civilians on both sides.

The separatists are clearly aware of their vulnerability, both in terms of security – their militias are a bewildering array of uncoordinated and poorly led military units – and in political terms – their inability to provide basic services for the population could seriously undermine their support base. They also admit an ambiguous relationship with Russia. They say that Moscow will intervene to avert major military or humanitarian catastrophes, but has no plans to recognise the separatist entities or provide major development or reconstruction aid. And they say that while Russia is playing a long game for the control of Ukraine, they are trying to stay alive for the next six months.

Renewed hostilities could take a number of forms. A Ukrainian offensive would almost certainly trigger a Russian military response, as Russian forces showed when in August 2014 they inflicted a devastating defeat on Ukrainian troops in Ilovaisk, near Donetsk city, stopping their hitherto successful offensive. The geographical status quo has prevailed since then. A ceasefire brokered in September has been largely ignored. A powerful group within the separatist leadership feels that they will not survive without more land, and clearly wants to resume offensive operations, in the belief that this would also bring in the Russians. Separatists are hoping for another “Russian Spring” – their term for Moscow-encouraged and fomented seizures of power in other south-eastern oblasts. And, should weather conditions impede resupply of Crimea by sea this winter, Moscow may intervene to open up a land route from the Russian border through Ukrainian territory. Either move would undoubtedly be viewed by the EU, U.S. and other supporters of Ukraine as a major escalation and lead to further sanctions.

EU and U.S. sanctions may well have deterred a further Russian advance along the Black Sea coast after Ilovaisk, and seem at the moment to be deterring any substantial separatist advance beyond the current frontline. They have also added to the pain of Russia’s economic downturn. The EU’s tough line on sanctions surprised Moscow, which assumed that consensus in Brussels would quickly disintegrate. But there is little sign that either the U.S. or the EU have thought about ways to de-escalate when the need finally arises. Russia is following a similar improvisatory path. It underestimated the implications of annexing Crimea or intervening in eastern Ukraine. It protects the entities from Ukrainian attack, but seems reluctant to do much more than that.

Improvisation needs to be replaced by communication between all sides. This would help defuse tensions, perhaps prepare the ground for consultations between the main warring parties, and allow all sides to concentrate on humanitarian assistance in the coming winter. Russia could confirm that it has no plans to recognise the separatists. It could reject the idea, often floated in Kyiv, of a major Russian offensive in the spring. Kyiv could similarly promise to refrain from offensive military operations during this period. It could spell out publicly and clearly to the people of the east what political solution it has in mind for their areas after the war, and offer a clear assurance that it will, with Western assistance, help rebuild the east. Such an approach by all sides would not only help Ukraine weather a dangerous winter, but also allow it to emerge in the spring with hope for the future.

This report concentrates largely on one of the lesser known aspects of the crisis – the thinking and capacity of the separatist leadership, their relationship with Moscow and their views of the future. It does not present an overall analysis of the U.S., European Union and member states’ policies on the crisis.