What is the cause of the recent flare up of tensions between the two Koreas?
One of my theory says that this is an Obama administration ploy to put pressure on China. This to achieve a Yuan revaluation that in the end is hoped to lower the U.S. trade deficit and revive its economy.
The economic part of this would unlikely work as hoped for. When Japan was pressed in the 1980s to increase the value of the Yen the U.S. trade deficit with Japan widened.
But besides that any tensions, even artificial ones, in the area are extremely dangerous as both Koreas are not under real control of their hegemonic overlords and things may just get out of hand with very serious consequences. The North, relying on a self sustenance ideology (juche), may not respect any restraining order it gets from Beijing and the very hawkish South Korean president Lee Myung-bak may escalate any situation without first asking for Washington's okay.
After his election Lee Myung-bak stopped nearly all cooperation and agreements with the North. While the "western" tale says that the South Korean ship Cheonan was sunk by a North Korean submarine I, like the Russians, have serious doubt that this is what really happened. The recent artillery exchange between the North and the South came after not necessarily helpful firing of South Korean artillery very near to the northern border. Are we sure that none of those first barrage rounds actually landed in North Korean territory?
Currently we are seeing a strong military buildup. The U.S. is deploying Joint STAR ground surveillance planes. The aircraft carrier group around the USS George Washington is deployed to the south-west of Korea while the carrier group of the USS Ronald Reagan is on its way to the area. Recently the so far biggest ever U.S. navy maneuver with the Japanese navy was immediately followed by one with the South Korean navy. The U.S. air force now transfers 30,000 tons of jet fuel from Japan to South Korea while the U.S. army is pre-positioning additional equipment in South Korea. South Korea is holding a nationwide emergency drill.
While that all may be part of some show Russia alerting its far-east forces is something different.
The current propaganda from the North has more bluster than usual:
A second Korean War would not fail to disappoint Western experts who wish to see Kim Jong-eun given an opportunity to prove his unprecedented military genius. He would preside over the evaporation of the world's sole superpower in the first thermonuclear exchange ever fought on the spaceship Earth.
That would certainly not happen. But any escalation would likely include a serious land war which South Korea and the U.S. may well "win" in the first few days, but in which any fast "victory" would immediately degrade into a protracted guerrilla war with China feeding whatever may be needed to its North Korean allies to keep the U.S. away from its borders.
Obama must pull the South Koreans back or this might explode very violently.