Kennedy's rebuke of Shah Reza Pahlavi in 1978 served to put pressure on the Iranian government to begin democratic reforms, and led to the dismantling of SAVAK in Iran.
Also, his pressure on the South African government won the release of Nelson Mandela from imprisonment in 1983. From what I remember of the period, Republican leaders like Jesse Helms and Ronald Reagan would have continued to support Botha and de Klerk regimes....
Also consider that without President Kennedy, the manned mission to Mars would have never been launched in 1992. Contrary to all the bullet points by the Republican Party, the Space Shuttle was a dead-end for NASA....
Just a matter of public record, Teddy Kennedy in OTL was an opponent of the space program and had actually called for the cancellation of all of the Apollo moon flights subsequent to Apollo 11.