From the series editor: This series on strategy began on Foreign Policy’s Best Defense site but now lives here. The next three articles in the series deal with practical aspects of strategy development and implementation, the stuff of executive and middle management. It is not enough to have a good strategic vision. People, organizations, and systems are required to implement it. This week, Air Force Lt. Col. (Ret.) Jon Herrmann describes a balancing act, common amongst leaders, that often derails effective strategy.  — Paul Edgar