It was Russia's invasion of Ukraine that precipitated Germany's decision to station a brigade permanently in Lithuania, about 100 kilometers (62 mi) from the Russian border, and help fortify NATO's eastern flank. Germany hasn't had a permanent military presence abroad since World War II. However, Berlin now sees how urgently it has to establish this force given the changing security landscape in Europe. If Russia wins the war in Ukraine, it might go after the Baltic states next.
Establishing this military force in Lithuania might not go as smoothly as Berlin may hope for. It will take some convincing to get thousands of German soldiers to volunteer for permanent service in Lithuania in addition to generous bonuses and other tax-free benefits. Moreover, considering the history, it seems improbable that the local populace will welcome Germans with open arms. This attempt to bolster NATO's eastern flank is fraught with challenges.