What can be inferred from the fact that the United States did not share its plans for building the atomic bomb with the Soviets during the war?

Because the soviet union was a communist regime and the americans were a capitalist country and this meant they really did not like each other but the only reason they fought together in world war 2 is because they had a common enemy that was more of a threat then each other (at the time) but during the end of the war the british and americans new they would have problems with russia so they started to prepare for what will ever come next (which was the cold war) by grabbing as much land as they could and not giving them technology like the atomic bomb