Joshua Stanton looks at the current crisis in Korea and what options South Korea may have short of war, which for a variety of reasons (some strategic, some more obvious) isn't really the best answer:

President Lee still has options.

First, he can stop feeding the beast - he can cut off South Korean economic aid to the North. For cosmetic purposes, he can offer to resume aid if Kim Jong Il cooperates fully with the investigation and personally apologizes to the sailors' families (don't worry; he won't). Lee can stop importing goods from North Korea and cut this flow of hard currency. The other main conduits of South Korean hard currency for Kim Jong Il include the Kumgang Tourist Project, whose property the North has just begun to confiscate anyway, and the Kaesong Industrial Park, which has fallen victim to North Korean political meddling and clearly won't ever become a profitable export manufacturing center now. Lee can also order his banks to take a more aggressive approach to enforcing the financial provisions of U.N. Security Council Resolution 1874. Politically, he should increase his government's support for a community of 17,000-plus North Korean defectors who are leading efforts to broadcast independent news back into their homeland, news that seems to have attracted a significant following in North Korea. He can increase the number of defectors his government admits, and do more diplomatically to force China to let would-be defectors in China travel to South Korea safely. He might even permit defectors to establish a North Korean transitional government-in-exile on his country's soil; after all, with proper education and training, those defectors could be a key part of President Lee's strategy to re-stabilize post-Kim Jong Il North Korea if, as seems increasingly likely, the Kim Dynasty ceases to exist within the next five years.

Stanton's piece got me thinking about a broader point. As a general matter, I'm not much convinced by the power of persuasion or the suasion of law in international affairs. And I don't believe that diplomacy is ever the answer to cause anything to happen; at best, diplomats exist to prevent things from happening, and to work out the endgame once sufficient force has been used or threatened.

War is the use of force, but it's not the only type, and during the Cold War we eventually got good at finding ways short of open war (including proxy wars as well as other tactics not involving military force) to impose costs on our adversaries for purposes of retaliation and deterrence. One of my ongoing concerns in the two decades since the Cold War is that as a nation, we seem to lack the will or the creativity to find meaningful ways to put pressure on misbehaving states short of bombing or invading them, which naturally means you end up resorting to force in the absence of meaningful alternatives. In some cases, it inevitably has to come to that anyway, but you'd like to keep those to a minimum. Economic sanctions regimes, for example, have proven all but impossible to enforce been riddled with corruption. Unlike the U.S. - and more like the U.S. relationship with Cuba - South Korea may actually have the leverage to use economic muscle in a way that has some real impact on the North without unduly harming its own economy (Stanton thinks so). But in the usual course - even recognizing that the best means of leverage against hostile governments sometimes happen far out of public view - too often we seem to lack the (for lack of a better word) deviousness to make tyrants awake every morning wondering what we will do to them.