From U.S. Army, 2012b, Pages 2-2, 2-4
2-9. Army forces demonstrate the Army’s core competencies through decisive action—the continuous, simultaneous combinations of offensive, defensive, and stability or defense support of civil authorities tasks. In unified land operations, commanders seek to seize, retain, and exploit the initiative while synchronizing their actions to achieve the best effects possible. Operations conducted outside the United States and its territories simultaneously combine three elements—offense, defense, and stability. Within the United States and its territories, decisive action combines the elements of defense support of civil authorities and, as required, offense and defense to support homeland defense….
2-18. Decisive action requires simultaneous combinations of offense, defense, and stability or defense support of civil authorities tasks. Table 2-1 lists the tasks associated with each element and the purposes of each task. Each task has numerous associated subordinate tasks. When combined with who (unit), when (time), where (location), and why (purpose), the tasks may become mission statements.
Table 2-1. Tasks of decision action