Beginning June 5, Lithuania is building a fence around the Russian exclave of Kaliningrad, Delfi reported. Citing smuggling and illegal immigration, the State Border Guard Service said that the 44.6 kilometers (27.7 miles) barrier should be completed by Dec. 20. Lithuania also plans to build a fence along the country’s border with Belarus by 2020. But Lithuania’s true motivations are likely driven by conventional military threats. Both regions will be key sites of Zapad 2017, the Russian, large-scale military exercises in September, and unconfirmed reports indicate that some Russian troops and equipment could be left in the area afterward. The Baltic-Belarus-Kaliningrad corridor is a key region for military buildups by both Russia and the West and will be worth watching for any flare-ups.