What impact did the cold war have on the delveloping world today?
The "Space Race" was an immediate spawn of the Cold War. The Cold War was pretty much the Soviet Union and the U.S. constantly 1-upping each other, and the lunar landing was just yet another 1-up by the United States. Without the Cold War, it is safe to assume that the U.S.'s space program would not be as advanced as it is today.
It is probably impossible to argue what had the greatest impact on world history, it did of course have a massive impact and we still see its legacy now, but there are other things that have had an impact that is still with us (from the Roman Empire through to the Cold War). I think this probably counts as either a question that cannot be answered, or one that should be answered simply as "No".