What were the causes and effects of the US boycott of the 1980 Olympics?

The US Olympic boycott of 1980 had its causes and effects
in the Cold War.  The US boycotted the 1980 Summer Olympics because of the Soviet
invasion of Afghanistan.  The US and the USSR were adversaries in the worldwide Cold War
at this time.  The US was concerned about the invasion and wanted to express its
disapproval in a way that would hurt the prestige of the Soviet Union.  Since the
Olympics were being held in Moscow that year, the US decided to deny the Soviets the
prestige of holding a truly successful Olympic Games.  The only real effect of this was
to chill relations between the two countries a little bit and to lead to a Soviet
boycott of the 1984 Summer Olympic games in the United States.