There are many things that had led up to ending of World War Two. Things such the invasion in Normandy, or the German forces not being able to take over Russian due to the winter. Non-however was more important then the strategic role that the atomic bomb had in bringing a conclusion to the war.
With the Manhattan Project, the invention of the Atomic Bomb not gave America very great power. It could use this power as just a threat and not use the bomb or as an actual occurrence.
After the United States gave Japan a warning and they still refused, on August 6, 1945, a B-29 bomber dropped an atomic bomb on Hiroshima, destroying the whole city in forty three seconds. This was a very big step in bringing a conclusion to the war because it showed Japan as well as the other Axis Powers the enormous strength that we posses. This strategy would later pay off with the surrender of Germany.
When Japan did not yet surrender, even with the major casualties they suffered, the United States dropping another bomb on Nagasaki was the only option to bringing an end to this war.
From the strategic point of view it did not only tell the rest of the world that the United States is in control, but more important then that, the dropping of the bomb led to the surrender of Japan. With Japan out of the picture the United States is safe, and Germany is without another ally leaving it with no choice but to finally surrender.
I feel that another important strategic move was not letting a lot of information out. Very few people know that there were only two bombs made. Germany took that as well into consideration when it finally surrendered. Still to this day if it was not for the dropping of the atomic bomb, we might have lost the war and living in Japan.