Sabre rattling or a precursor to war?

North Korea is threatening to use "resolute military action" in response to the latest UN sanctions against it as well as insisting that it will continue its nuclear weapons programme.

This isn't anything new, of course, but as North Korea becomes more and more isolated I wonder if this isn't the usual sabre rattling of a pariah state, but an attempt to justify an attack on South Korea?

When a regime like NKs is pushed into a corner and left with nowhere to go there is always the temptation for a final throw of the dice - and NKs leadership is barmy enough to go all the way. If the US or anyone else, in accordance with UN sanctions, do begin to intercept NK shipping I can see the NK government using this as justification for declaring war and invading South Korea.

Unlike most people, I don't share the view that this would result in a massive defeat for NK - if they get the strategy right. South Korea is hardly a big country being little bigger than Wales and its capital and main port are barely inside the border with NK. And with South Korea having no land borders other than that with the north they are reliant on getting reinforcements and heavy supplies from the USA through those ports.

South Korea does have huge and highly capable armed forces of its own, though, but if NK could strike fast enough and effectively enough to deprive South Korea of its main air and sea ports then they could soon have a stranglehold on the south. And if they fail, they do have the nuclear option.