To be awarded to units of the United States Armed Forces for extraordinary heroism in action against an armed enemy of the United States while engaged in military operations involving conflict with an opposing foreign force or while serving with friendly foreign forces engaged in an armed conflict against an opposing armed force in which the United States is not a belligerent part for actions occurring on or after 3 August 1963. The VUA requires a lesser degree of gallantry, determination, and esprit de corps than that required for the Presidential Unit Citation (PUC). Nevertheless, the unit must have performed with marked distinction under difficult and hazardous conditions in accomplishing its mission so as to set it apart from the other units participating in the same conflict. The degree of heroism required is the same as that which would warrant award of the Silver Star to an individual. Extended periods of combat duty or participation in a large number of operational missions, either ground or air, is not sufficient. This award will normally be earned by units that have participated in single or successive actions covering relatively brief time spans. It is not reasonable to presume that entire units can sustain Silver Star performance for extended time periods under the most unusual circumstances. Only on rare occasions will a unit larger than a battalion qualify for this award.