Short answers, pulled from the story.
The United States boycotted the Moscow 1980 Summer Olympics to protest the Soviet invasion of Afghanistan in December 1979. President Jimmy Carter set a deadline for Soviet withdrawal and warned of consequences including an Olympic boycott if they failed to comply.
Sixty-eight National Olympic Committees plus Qatar did not participate, including Japan, West Germany, China, the Philippines, Chile, Argentina, Norway, Taiwan, Israel, and Iran. These nations withdrew their teams or refused to send delegations due to support for the U.S. boycott or political reasons.
Many athletes who had trained their entire lives missed the opportunity to compete at the Games. Events such as the Liberty Bell Classic and the USGF International Invitational were staged separately to provide alternatives for those sidelined by political decisions.
Athletes from 16 countries competed under the Olympic flag rather than their national flags because their governments officially supported the boycott. Four competitors from New Zealand marched under their NOC flag while other participating nations raised Olympic flags during medal ceremonies.
A Federal District court in Manhattan approved the settlement of two suits involving more than 9,000 Americans on April 1981. The agreement increased reimbursements so that those who canceled before the 1st of March 1980 received 85 percent of costs and those canceling after received 63 percent.