The Cold War had both positive and negative lasting effects on different countries in the world. Some countries that were formerly under Communist regimes are today enjoying higher standards of civil liberties compared to the situation before and during the Cold War. However, other countries have continued to suffer from the fall of these regimes, which left power vacuums in their respective countries. Today some of those regions (Southeast Europe among others) remain unstable due to civil conflicts caused by political instability.
Although the Cold War led to increased development of nuclear weapons for military engagement, the period after the war has seen more developments of nuclear technology in science, especially in the field of medicine, energy, and industry.
The war resulted in far-reaching foreign policies by the stronger nations aimed at maintaining the global status quo. Thus, the two countries continue to be involved in the affairs of other countries.
This a great question. There are so many lasting effects of the Cold War. Here are a few of them.
First, owing to the Cold War there is massive proliferation of nuclear weapons. We can destroy the world several times over. These weapons still exist. And if a rogue group got hold of one of them, it could create havoc in the world.
Second, Russia was hurt gravely. Many Russians were employed in the military sector. When the Cold War ended, these people not only lost their jobs, but the economy on a larger scale was damaged.
Third, many people and nations were involved in proxy wars, especially in places like Southeast Asia. So, the toll on humans lives was tremendous, not to mention that there are still bitter feeling in various places around the world. So, the legacy of the Cold War still exists.
Fourth, in the end, it led to the United States becoming the superpower of the world.