The presence of "rogue allies" was one of the costs involved in engaging in such strategy, as they had the potential to use aggressive behavior unilaterally that could have involved the U.S. in more military conflicts. The "rogue allies" which the U.S. leaders were worried about include Taiwan's Chiang Kai-shek, who was planning to take back mainland China, and South Korea's Syngman Rhee, who wanted to unify the Korean Peninsula, and they were also worried that Japan was recovering its regional power in Asia. With a thorough investigation on several empirical case studies of Taiwan, South Korea, and Japan during the Truman and Eisenhower administrations, Cha concludes that the postwar U.S. planners had selected this type of security architecture because it offers the safest architecture to prevent aggression by East Asia's pro-West dictators and increases leverage and the states' dependency on the U.S. economy. Now the word “powerplay” is commonly used in any political or social situation when one uses its knowledge or information against another in order to gain benefit based on one's situational advantages.