The paper deals with the question to what extent did the inauspicious end of the Prague Spring (i.e. Soviet led invasion of Czechoslovakia) affect the policy of Western nations, in particular the United States, toward the Soviet Union, and to wht extent was the August intervention an important factor in the development of the East-West relations? The conclusion based on the assesment of relevant documents from US archives is that the liquidation of the Prague Spring did not cause any fundamental problem for, or hiatus in, the policy of détente. If it did, then only for a short period of time or indirectly.