There have been other escalations in eastern Ukraine since the cease-fire took effect, but what sets this one apart is its consistency along most of the contact line. Generally, previous upticks in fighting were localized skirmishes that stretched out over time or briefly involved a higher volume of fire. Now, however, separatists are moving heavy equipment, including howitzers and multiple rocket launchers, back to the front line and consistently increasing the volume of fire directed at Ukrainian positions across different sectors. Monitors from the Organization for Security and Co-operation in Europe have documented the disappearance of these pieces of heavy equipment from the warehouses where they were stored after their withdrawal from the front line. Increasing reports of Grad rocket artillery strikes and intense tube artillery shelling indicate that the weapons are back on the front line. This is an explicit violation of a part of the Minsk II agreement that largely had been adhered to before.
That said, the massing of forces and heavy equipment on the front line does not bear the hallmark of a large Russian conventional military offensive designed to seize large areas, such as a push to the Dnieper River or an attempt to create a land bridge to Crimea, as some suggest is being planned. With the equipment and forces present on the line of contact, a wide range of potential military objectives — including a static continuation of intense fire on Ukrainian positions or a return to localized separatist offensive that could result in smaller territorial gains — could be achieved.
The most intense escalation has occurred around the city of Donetsk and in areas between Donetsk and Luhansk. If separatists are planning an offensive here, they could attempt to expand their presence around Donetsk or even push to regain control over Slavyansk and Severodonetsk. Although the Mariupol sector has been relatively calm compared with previous escalations there, additional actions in that area cannot be ruled out.
Such military actions would not achieve Russia's major strategic goals in terms of territorial gains, but they would send the kind of message Russia would be expected to broadcast to the European Union and the United States. Because the removal of sanctions is not expected in the immediate future, Russia likely would want to remind the West that there are very real reasons to adopt a more accommodating stance toward Russia. At the very least, the escalation highlights the fact that, given the extended European sanctions, Russia feels no immediate need to restrict the actions of eastern Ukrainian separatists and could in fact be pushing the escalation.
Logistical constraints on the separatists mean that without continued Russian supplies, these escalations cannot continue indefinitely. Although substantial reserves of ammunition are positioned within eastern Ukraine, the longer-term feasibility of the rebellion depends greatly on Russia's assistance. Thus, actions in eastern Ukraine are just some of the many elements in the higher-level negotiations between Russia and the West. Technically, both want a de-escalation of the situation, but actions along the line of contact will reflect the much broader interaction between the two sides.
