The Silver Star is currently awarded by all branches of the armed forces to any person who, while serving in any capacity, is cited for gallantry in action against an enemy of the United States while engaged in military operations involving conflict with an opposing foreign force, or while serving with friendly forces against an opposing armed force in which the United States is not a belligerent party.
The Silver Star medal had its beginning during World War I. An Act of Congress of July 9, 1918, authorized the wearing by Army personnel of a small silver star, three-sixteenths of an inch in diameter, upon the service ribbon of a campaign medal, to indicate "a citation for gallantry in action, published in orders issued from headquarters of a general officer, not warranting the award of a Medal of Honor or Distinguished Service Cross." Known in the Army as the "citation star," the award was made retroactive, so that all those cited for gallantry in action in previous campaigns, even as far back as the Spanish-American War, were eligible to wear it.
It is estimated that more than 20,000 members of the Army received such citations before 1918. A similar device was authorized for Navy and Marine Corps personnel in 1920 which authorized a " special letter of commendation" to be awarded on the recommendation of the Board of Naval Award. Receipt of this special letter of commendation authorized its recipient to wear a small silver star on the ribbon of the Victory Medal.
The Army announced that anyone who had previously earned a Citation Star could apply for the Silver Star medal. Navy and Marine Corps personnel could only apply, if they were awarded a citations star by the Army. The status of the Silver Star was further clarified, when on Aug. 7, 1942, Congress authorized the award of the Silver Star to any person who, while serving in any capacity with the Navy since Dec. 6, 1941, distinguished himself by gallantry and intrepidity in action, but not of a nature to justify the award of the Navy Cross. Four months later, on Dec. 15, 1942, the decoration was extended to Army personnel for gallantry in action, but not of a degree to justify an award of the Distinguished Service Cross.