Sun Tzu asserts that success is not winning every battle fought, but subduing the enemy's will without fighting. Nevertheless, modern military thought fails to distinguish an enemy's will-to-fight from their means to do so, limiting the ways military leaders apply operational art, problem framing, and conflict termination in pursuit of strategic objectives. The author asserts that gaining and maintaining a position of relative advantage for favorable conflict resolution requires leaders to understand the enemy's will-to-fight with equal fidelity as their means. This study examines U.S. planning efforts for post-WWII Japan from 1942 to 1945, focusing on the options planners possessed to achieve their ends; their choice to safeguard the Japanese Emperor; their understanding of the Japanese will-to-fight; and the way planners developed that understanding. The record reveals that--despite more forceful options--planners favored safeguarding the Imperial Institution; planners considered the Japanese people's will-to-fight as inexorably linked to the condition of their Sovereign, increasing in response to threats against Japanese national identity; and planners developed this understanding through discourse among experts in diplomacy, military governance, political culture, anthropology, and military intelligence. The implication--an enemy's will-to-fight can be targeted separate from their means and doing so may not require fighting. 2012-01 Outstanding Monograph Winner originally titled: Will-to-fight: Japan's Imperial institution and the U.S. strategy to end World War II.