Russia's Kaliningrad exclave is heavily militarized but geographically isolated, sitting on the Baltic Sea between NATO members Poland and Lithuania.

Its location makes it strategically valuable to Russia, and potentially vulnerable in any direct confrontation with NATO.

Heather Williams, director of the Project on Nuclear Issues at the Center for Strategic and International Studies, joins DW to examine how seriously NATO should take Moscow’s latest warning, whether nuclear threats have become an effective tool of Russian deterrence, and how an unintended incident around Kaliningrad could escalate into a much larger confrontation.