Conspiracy theorists would imagine that the Americans engineered the sinking of South Korean ship Cheonan — and pinned it on North Korea — as a means of pressuring Japan to agree to relocate the disputed Marine Corps air base on Okinawa. But conspiracies don’t work that well; only the natural course of events produces such ironies.

Shortly after Seoul announced its findings last week on the Cheonan sinking, Prime Minister Yukio Hatoyama publicly reversed his position on relocating the U.S. base. Vocal Okinawan activists have long wanted the U.S. Marine Corps out of their archipelagic prefecture entirely. Hatoyama promised during his 2009 campaign to revisit the previous government’s agreement to move the air base from its current position at Futenma to a new location in the Henoko district. And late last year he did just that, producing a months-long standoff with the U.S. over the fate of Marine Corps basing in Japan.

The Obama administration’s stance has been unyielding and less than cordial: December saw a painfully undiplomatic sequence in which President Obama refused a request for a sidebar with Hatoyama at the Copenhagen environmental summit; the Hatoyama government announced that it would not move on the basing matter at all until May 2010; and Hillary Clinton summoned the Japanese ambassador to lecture him on his government’s obligations under the previous agreement.

In spite of this unpromising history, however, the Hatoyama government has now agreed to continue with the plan to move the air base to Henoko. The move remains deeply unpopular in Okinawa, but Hatoyama is quite explicit about his reason: his concern for Japanese security in light of the tensions on the Korean peninsula.

This is a pyrrhic victory for Obama’s diplomacy. The alliance with Japan is worth tending better; it might have been possible to achieve this or a similarly advantageous outcome without leaving Japan’s government and the Okinawans feeling cornered and resentful. But our “smart power” administration didn’t even try.

Events will not always yield blind luck and drive our allies to do what we want. With events likely to begin piling up faster than we can react to them, greater care is called for. Observing with our allies the basic norms of courtesy, access, negotiation, and compromise would go a long way toward cementing our commonality of purpose as the challenges to our global security arrangements accelerate.