Oct. 23, 1962 - The Kennedy Administration believes its blockade of Cuba caught Moscow off guard and interrupted a well-mapped Soviet effort to force a humiliating Berlin settlement upon the West. The initial response from the Kremlin today was judged in Washington to be relatively mild and hesitant. It was read as confirmation of the impression that the Soviet leaders had been thrown off stride. After a momentary respite however, President Kennedy and his advisers are said to expect a serious Soviet counterchallenge, probably in Berlin. Officials said that they were ready for a two-front showdown. The Western position in Berlin, they insisted, is non-negotiable. However, some sources said that if the Russians wished to engage in negotiations for the dismantling of offensive missile bases in Cuba, it was conceivable that the U.S. might be willing to dismantle one of the obsolescent American bases near Soviet territory. Polaris-equipped submarines capable of striking almost any Soviet target are now on constant patrol and have assumed many of the functions of American bases near Soviet frontiers, officials said.