President Jimmy Carter decreed that the US would boycott the 1980 summer games, which happened to be held in Moscow, as a protest against the Soviet Union's invasion of Afghanistan in 1979.

The Soviet Union retaliated by not going to the 1984 summer games, coincidentally being held in Los Angeles. The stated reason was that they think the athletes would be safe in LA, which was a made-up excuse--everybody knew it was in retaliation for the 1980 boycott. All of the other Eastern bloc countries bowed to Soviet pressure and also boycotted the 1984 games, with the exception of Romania. The Friendship games were a propaganda tool where the Soviets could showcase their athletes in 1984 while providing counter-programming to the Olympics. Basically, they hoped to gain attention for their athletes who otherwise would not have a global competition, and also reduce enthusiasm for the Olympics by having a similar athletic event in the weeks before the Olympics. Since non eastern bloc countries didn't take the Friendship games seriously, they didn't send their top athletes. The top athletes were all going to the Olympics and wouldn't want to disrupt their training schedule or risk injury to attend a different event.