Six Ukrainian troops were killed over the weekend near rebel-held Donetsk, in a shift from the relative calm in the region since a ceasefire took hold in September. Ukrainian President Petro Poroshenko has warned that Ukrainian forces will return fire when troops’ lives are under threat and that Kiev will return artillery and mortars to the frontlines should an escalation take place. While on the surface these clashes point to an escalation between Ukraine and Russian-backed forces, evolving geopolitical dynamics both in Eastern Europe and the Middle East indicate that there is an emerging understanding between the U.S. and Russia. The latest outburst of violence in eastern Ukraine forms part of this negotiation.

The uptick in casualties due to clashes with Russian-supported rebels comes just as Ukraine formally received, on Nov. 14, two AN/TPQ-36 counter battery radar stations from the U.S. military. The clashes also took place on the weekend that foreign ministers from the world’s major countries met in Vienna in an attempt to formulate a roadmap for Syria’s future β€” a meeting that was pre-planned but whose dynamics completely shifted following the Nov. 13 Islamic State attacks in Paris. It was also the weekend that U.S. President Barack Obama and Russian President Vladimir Putin met on the sidelines of the G20 meeting to discuss both the crisis in Syria and the situation in Ukraine.

The crises in Syria and Ukraine are intimately connected. The U.S. and Russia use their positions of influence in the two conflicts as bargaining chips in negotiations. The U.S. is preoccupied with maintaining a balance of power in the Middle East without directly intervening in Syria and entering a prolonged and costly war. Russia is worried about the status of Ukraine and preventing a U.S. or NATO military presence in what the Kremlin considers Russia’s chief buffer zone. The U.S. has plenty of leverage in Ukraine: it has supported the pro-Western government financially and has the ability to provide significant military assistance to the Ukrainian armed forces fighting Russian-backed rebels.

Russia, on the other hand, is trying to create leverage in Syria by carrying out airstrikes against the Islamic State and rebel targets. The Kremlin is helping safeguard the Syrian regime and ensure its survival because it believes this to be the most effective strategy for combating the region’s jihadists. Backing the Bashar al-Assad regime is much more difficult for the United States because of the hardline it has taken on Assad’s presence in the past. In the current struggle for the U.S., the most important thing is to beat IS and it is understood that backing Assad can help achieve this goal. This is something Russia can do and is doing, with far fewer complications than the U.S.

The Americans have the ability to help Russia fulfill its goal of at the very least keeping Ukraine neutral. At the same time, the Kremlin can help Washington further its goal of maintaining a balance of power in the Middle East without a significant American military commitment. Meanwhile, the Islamic State has targeted Russian and French civilians, and has threatened to expand its operations as far as Washington. The U.S. and Russia share the goal of limiting the Islamic States’ power and ability to operate globally. Moscow and Washington, therefore, would benefit from cooperation: both sides have something to offer that the other side seeks.

In negotiations, all sides have an incentive, during critical moments of the negotiation, to threaten to walk away from the negotiating table. On a weekend when President Obama and President Putin sat down to discuss Ukraine and Syria, the delivery of the U.S.-provided battery radar stations and the increased hostilities in eastern Ukraine can be seen as a negotiating tactic. As Russia and the U.S. come closer to an understanding on the status of Ukraine and their approaches to Syria, showing off of levers and threatening to leave the negotiating table can be expected but do not signal an end to negotiations.