MY COLLEAGUE is exactly right that everyone agrees that America has "no good options" for responding to North Korean aggression. But given that everyone agrees America has no good options for deterring further provocations or for moving towards a stable resolution on the Korean peninsula, it's worth broadening the perspective a bit and looking at whether America can use this incident to achieve any of its other geopolitical goals. In fact, from certain perspectives, incidents like yesterday's shelling attack are quite helpful for American diplomacy. Which bears to a certain degree on my colleague's overarching question of whether the United States benefits by acting as a global security guarantor.

One goal of American foreign policy these days is to guarantee that America has options for counterbalancing rising Chinese power in the Far East. American officials would never state such a goal in so many words, as that would be obnoxious and unnecessarily provocative. Officially, we welcome China's rise as a partner in guaranteeing global stability and prosperity, and so forth. But if there were any doubt that the United States were engaged in a competition with China for East Asian sympathies, Hillary Clinton's efforts over the past six months to align America with southeast Asian countries and Japan against Chinese maritime territorial claims should have dispelled them. Incidents like the shelling attack are quite helpful for American diplomacy, because they are blamed partly on China's failure to restrain its psychotic North Korean nephews. The damage to Chinese prestige put the Financial Times's Geoff Dyer in mind of the laments he heard from a Chinese official during Barack Obama's world tour this fall:

As Barack Obama was visiting Asia earlier this month, his friendly reception in country after country provoked a somewhat forlorn response from one Chinese official. “Look around the world, the US has dozens of well-established alliances,” he said. “We only have one.”

That one being...North Korea. Events like the shelling attack on South Korea enhance American relations with South Korea, Vietnam, Japan, the Philippines, and to some extent Indonesia, India, Thailand, and any other country that worries about how China will behave in its region. In other words, when North Korea goes nuts, American soft power grows. Unfortunately, that kind of American soft power is based on the availability of American hard power. Countries turn to America in the face of North Korean madness because America is the only country that can dispatch a carrier task force into the Yellow Sea.

The question my colleague asks, however, remains: why do we care? What American interests are at stake in the security positions of East Asian states vis-a-vis China? United States Navy officers routinely explain their presence in regional waters as guaranteeing that sea lanes will remain open for trade. But who is threatening to close sea lanes? No country in the world has more interest in open sea lanes than that great export nation, China. Do we really need 11 carrier task forces to protect something nobody is threatening? Wouldn't eight be enough? In other words, it seems to me that America's security presence in east Asia is helpful to the American goal of counterbalancing Chinese geopolitical weight. The question is why we're trying to counterbalance Chinese geopolitical weight, and at the deepest level, that seems like a hard question to answer.

On the other hand, Sarah Palin's proposed Nixon-to-China gambit of switching sides in the Korean conflict has been insufficiently explored. If anybody can pull it off, she can.