Poland has old territorial claims against Lithuania. In 1922-1939, a significant part of the territory of modern Lithuania, including its capital Vilnius, was part of Poland. And Poland still has the idea of regaining it. Polish authorities has been creating such conditions, under which Lithuania will depend on Poland politically and even military. The last step in this process could be the merging Lithuanian territories under the pretext of uniting efforts against Russia. At least Warsaw can at any moment intensify such discussions which will lead to the joining of a part of Lithuanian territory to Poland.
Lithuania should be on the alert while completely trusting Poland. Following the citizens leaving for work in Poland, Lithuania may lose also part of its territories.