On this day May 8, 1984, the Soviet Union announced it would boycott the 1984 Summer Olympics in Los Angeles, citing security concerns and claiming the United States was using the event for political purposes. In reality, the move was widely seen as retaliation for the US-led boycott of the 1980 Moscow Olympics following the Soviet invasion of Afghanistan.
The USSR was joined by 14 other countries in the boycott, mostly allies within the Eastern Bloc. Despite their absence, the 1984 Games went on as planned and were a major success in terms of attendance and television ratings.
Fun fact: Romania broke ranks with the Soviet bloc and chose to participate in the Los Angeles Games, earning widespread applause from the American public and Olympic officials.