There is another aspect to the so-called crisis on the Korean peninsula. Let me start by saying that any thought of some similarity in national sentiment between the North and the South is likely wrong. Why? To understand this we have to go back in history, to the time when Korea became divided, a division that reflected not just political differences, but an ideological difference, also. That ideological difference developed during the 35 year Japanese occupation of Korea. Japan made a determined effort to turn the Koreans into Japanese. Anyone wanting to get on in life, accepted that and became, at least, Japanese sympathisers. During WW2 many Koreans fought in the Japanese army. But other Koreans went the other way, and became underground fighters against the Japanese occupation. The first President of the northern Democratic People's Republic of Korea, Kim Il Sung claimed to be one of those guerilla's. IF so he lived on the edge for years, continually hunted by the Japanese Army both in northern Korea and in Manchuria, which the Japanese had seized from China and re-named it as Manchukuo. When finally things got too hot for him, he fled into Russia, where the Russian army inducted him into the Russian army. It was there, as he watched the massive USSR build up in 1945, that he likely became enamoured with the power of a centralised state and became a communist. This division between those who fought the Japanese occupation and those who helped the Japanese created enormous bitterness. There were other factors also, the western powers had given little thought to the Koreans and were very ignorant of what was happening. If the Americans and English had been better informed, the division between the Communist north and the so-called free south may not have occurred.
But when the division did come, anyone in the North that had been a Japanese sympathiser, or served in the Japanese Army fled to the south. While others for the opposite reasons, fled to the North. In the north the USSR selected Kim Il Sung as leader, and in the south the Americans selected an exiled Korean Syngman Rhee as their choice and 'parachuted' him into the Republic of Korea as President. Rhee was fervently anti-communist and both the north and south, convinced that their way was the only war, commenced a military re-armament in order to unite Korea under one government by force.
In those years the north made greater progress in industrialisation and re-building than the south, some, at least of that progress was from Soviet assistance. In later years the south has done better, due to an extent to American assistance.
So how, if it became possible, would these two ethically identical, but ideologically separated peoples, ever be united into one national group again. It is thought by many scholars of the Koreans, that would be a far greater problem than faced divided Germany.
Some think it could cost something like 3 trillion dollars and to take years to achieve.
Ideollogically, the north fits better into modern China, (and, remember the border provinces of the Dongbei (the former Manchukuo) have a large population of ethnic Koreans) but it is difficult to see whatever form a replacement government for the Kim regime may take, its difficult to see it agreeing to unite with China. And considering the even greater bitterness between the north and the south, it is unlikely that they would agree to unite with the south. It may be then, that there can be no unified Korea.
If any military action decimates sections of the north, who will pay for it to be re-built? It is thought by many, that the southern population will not want to pay for the north, another reason to think that there will be two Koreas in the foreseeable future.
When the west considers any military strikes, they should be considering the possible result if the north collapses. It comes back to the solution I mentioned in a previous post advocated by a former Australian PM - No sanctions, No unnecessary military action- and Yes! do everything possible to build a strong middle class.