Psychological operations are planned propaganda operations to convey selected information and indicators to foreign audiences to influence their emotions, motives, objective reasoning, and ultimately the behaviour of foreign governments, organisations, groups, and individuals.
The purpose of United States psychological operations (PSYOP) is to induce or reinforce behaviour favourable to US objectives. They are an important part of the range of diplomatic, informational, military, and economic activities available to the US. They can be utilised during both peacetime and conflict. There are three main types: strategic, operational, and tactical. Strategic PSYOP include informational activities conducted by the US government agencies outside of the military arena, though many utilise Department of Defense (DOD) assets. Operational PSYOP are conducted across the range of military operations, including during peacetime, in a defined operational area to promote the effectiveness of the joint force commander's (JFC) campaigns and strategies. Tactical PSYOP are conducted in the area assigned to a tactical commander across the range of military operations to support the tactical mission against opposing forces.
PSYOP can encourage popular discontent with the opposition's leadership and by combining persuasion with a credible threat, degrade an adversary's ability to conduct or sustain military operations. They can also disrupt, confuse, and protract the adversary's decision-making process, undermining command and control. When properly employed, PSYOP have the potential to save the lives of friendly or enemy forces by reducing the adversary's will to fight. By lowering the adversary's morale and then its efficiency, PSYOP can also discourage aggressive actions by creating disaffection within their ranks, ultimately leading to surrender.
http://en.wikipedia.org/wiki/Special:Search/Psychological_Operations_United_S...
[US Army] Introduction to Psychological Warfare - GF33-27 (1955)
