The Berlin Crisis reached its peak in the fall of 1961. Between August and October of that year, the world saw the United States and the Soviet Union face each other across a new barrier of the Cold War, the Berlin Wall. In a sense, the Wall was Khrushchev's response to Kennedy's conventional policy in late July, and there were some in the West who saw it that way. However, as Hope Harrison has clearly demonstrated, Khrushchev was not the dominant player in the decision to raise the Wall, but rather acquiesced to pressure from East German leader Walter Ulbricht, who saw the Wall as the first step in resolving the problems political and economic leaders of East Germany. difficulty. The most pressing of these difficulties was the refugee problem, which reached its peak in the summer of 1961 when thousands of East Germans reacted to rising tensions by fleeing westward. But Ulbricht also saw the Wall as a way to assert East German primacy in Berlin, and thus as a way to increase pressure on the West to accept East German sovereignty over all of Berlin. a precursor to the Soviet peace treaty, which would have ceded control of Berlin's access to East Germany, forcing Western recognition of East Germany or a confrontation that could have led to war. It appears, however, that Ulbricht was the only player who viewed the Wall in this way. Khrushchev was still willing to keep the peace treaty and ultimatum on the table, but was increasingly concerned that the United States and the West would not buckle under pressure and that Ulbricht's path was more likely to lead to the latter result. He thus began to withdraw, slowly, from the confrontation over Berlin, just as he had done in 1959 and... halfway through the document... the lanning certainly took on a new urgency, focusing mainly on how to integrate American and NATO conventional integration into existing and new plans. The Kennedy administration in particular was interested in resuming work in LIVE OAK, on ​​the basis of what it hoped would be a new NATO force proportional to the new American force. But their hopes have been dashed by the reality of Alliance politics, as both NATO strengthening and renewed contingency planning have consistently fallen short of what Americans expected. Not only were the Allies unwilling to spend the money and resources necessary to increase their front-line conventional force, but they were also concerned that such a buildup would undermine nuclear deterrence, and so they were intent on obtaining Kennedy's guarantee that the foundations of NATO The strategy, namely the timely use of nuclear weapons, was still in force.