Alliances and policies have a way of shifting quickly, at opportune or even inopportune moments. What is President Xi Jinping doing in Seoul this week, and why are the Japanese talking to the North Koreans? For that matter, how come Japan is revising its strictly no-war policy so that its forces can aid foreign friends in "collective self-defence"?
Having long since established an army, navy and air force as strictly "self-defence forces", Japan is now rationalising a great leap forward in which Japanese ships and planes could join its ally, the US, in fighting for Japanese interests. One obvious scenario: a northeast Asian war exploding out of armed conflict on the Korean peninsula or a Chinese attack on the Senkakus/Diaoyus.
Could it be entirely coincidental that Japan's hawkish prime minister, Shinzo Abe, came out with this "proactive" policy shift just as South Korean President Park Geun-hye was about to greet Xi for two days of summitry? And how was it that Japanese and North Korean diplomats were meeting in Beijing to talk about the fate of Japanese citizens kidnapped to North Korea?
Kim Jong-il acknowledged the kidnapping in 2002 in a summit in Pyongyang with Junichiro Koizumi, then Japan's prime minister. At his side, urging him to demand an apology, was Abe, then Koizumi's aide.
As if these coincidences were not enough to inspire conjecture about slowly shifting alliances, there's also North Korea's launch of short-to-medium-range missiles. These carried a message: Pyongyang is pushing ahead with its missile-and-nuclear programme at a time when the president of its greatest friend, its source of food and fuel, has chosen to visit South Korea ahead of the North. Could there be any better way for Kim Jong-un to show off his own style of leadership?
Interestingly, although Pyongyang's Korean Central News Agency hinted at "pre-emptive" strikes against its enemies, the US was not even an imaginary target since these missiles were not long-range models of the sort that put a satellite into orbit in 2012. South Korea and Japan were obviously in range, but how about China? North Korea is not about to go to war with its powerful protector, but China is certainly viewed with open hostility by many at the highest levels in Pyongyang.
Actually, the confluence of such signals in a very brief period may work in South Korea's favour. As China and South Korea expand trade and investment, the North poses an increasingly negligible threat despite the prospect of a fourth nuclear test. Just as North Korea is not going to menace China militarily, so it's not going to put its huge investment in horrific weaponry to real use. South Koreans are right to be bored by the rhetoric.
What about the Chinese challenge on the Senkakus and the US-Japan and US-Korea alliances? Will Japanese ships and planes support the Americans on operations from the East China Sea to the South China Sea and beyond? And how would South and North Korea respond if conflict broke out? On the chessboard of northeast Asian rivalries, the players are making moves that may change the nature of the game.
Journalist Donald Kirk is the author of three books and numerous articles on Korea