On October 12, 2000, the USS Cole was attacked by a small band of Islamic (global) insurgents. Why would sea insurgents attack a professional warship that did not appear to be related to counterinsurgency? When are such attacks successful, and when are they not successful? Three dimensions-value, vulnerability, and learning-give convincing answers to this puzzle. I trace two cases: the USS Cole bombing and the USS Ashland and Kearsarge missile attack. I find that when the navy is equipped with a fast learning process and this reduces its vulnerability, sea insurgents' attacks are less successful. This strategic interaction dynamic is strongly applicable to South Korea under three subdynamics: alliance, commitment dilemma, and enhanced naval capabilities. Thus, the Republic of Korea Navy needs to establish a flexible strategy in its effort to effectively deal with nontraditional threats as well as traditional threats, such as North Korea.