- The US and USSR were engaged in an intense strategic nuclear arms race during this period, developing technologies like MIRV warheads. - The US significantly expanded its involvement in the Vietnam War through large-scale bombing campaigns and increasing troop deployments on the ground. - There were many important events that shaped national security policy during this time, including the Dominican Republic intervention, escalation of the Vietnam War, the 1967 Middle East War, and the 1968 Tet Offensive and Soviet invasion of Czechoslovakia.