The differences in approach and culture between the U.S. Departments of State and Defense are stark despite the fact that these organizations are members of the same team and share related national objectives. Understanding the nature of these differences is key to improving interagency cooperation between the two key agents of our national foreign policy. State’s historical role as the nation’s lead instrument of foreign policy has eroded since World War II, while Defense has seen its power and influence grow. Our nation’s diplomatic efforts aim at exhausting opportunities to secure peace and stability before turning to the option of last resort. Defense is no less pleased than State when diplomatic efforts fail and military force is applied.