I’m with Rob at LGM on this issue: if the North Koreans torpedoed South Korea’s Cheonan, doing nothing is not an ideal response. As Rob notes: “indicating that North Korea is allowed to sink South Korean ships in internationally recognized South Korean waters seems problematic.”
However, if I’m remembering my Robert Jervis correctly, we should be careful about assuming that North Korea was acting as a rational, unitary actor (I think Jervis used the phrase centralized and coordinated) in this instance. This is a classic type of misperception. And Rob suggests this as well, writing: “It’s simply not the case that the order to escalate MUST have come from Kim Jong Il, although it’s certainly POSSIBLE that it came from the top.” Unfortunately, it is hard to know which it was – and doing nothing could certainly send the wrong signal north. However, overreaction would also be a mistake. Yet another reminder that having the responsibility of power is a heavy burden.