In case you haven't noticed, the nuclear arms issue is back — in its strategic rather than its tactical or battlefield dimension.
That's true not only in North Korea, but in Russia as well. It has deployed Iskander missiles (known as the SS-26 in NATO-speak) in the enclave (some call it an exclave) of Kaliningrad, the capital of which is the former Koenigsberg of Immanuel Kant.
These missiles are capable of carrying nuclear payloads (whether they do in fact carry them is unknown). Russia made its move in response to the deployment of 4,500 allied troops in Poland and the Baltic states.