Russia's actions in Kaliningrad, which is basically the old East Prussia, pose a threat to NATO if Russia wages war on the alliance:
US military officials say they are concerned by what they call Russia's ability to establish "anti-access/area denial" capabilities, or, weaponry that reduces NATO's potential freedom to maneuver in the region. Those include some of the modern weapons systems stationed in Kaliningrad, including anti-ship missiles, radar systems and surface-to-air missiles.
The improvements include nuclear capable missiles, but no word of actual nuclear weapons.
If Germany is serious about rebuilding their military, I think the joint German-Dutch corps should have the wartime mission of spearheading an offensive to take Kaliningrad or at least compress the perimeter into a small enough area that it poses no threat to NATO logistics and is incapable of supporting a Russian offensive.
Thus far, I believe that Russia's ground garrison has only 3 brigades. And those brigades are much weaker than an American or comparable Western brigade.