A U-2 spy plane flying was caught over Cuba near nuclear missile sites. These missiles were more than capable of reaching the United States. The President, Which was Kennedy, called a small group of senior officials to debate about the crisis. The group known as ExComm, met continuously for the next two weeks. The group had been split between those who wanted a military solution, and those who wanted a diplomatic solution. Some time later, President Kennedy ordered a naval blockade. DEFCON 3 is an increased readiness in force greater than that required for normal readiness. ICBMs were prepared for launch, Polaris submarines were dispatched, and the B-52 bombers were placed on alert. Khrushchev put Warsaw Pact forces on alert. Later, U.S. forces were placed on DEFCON 2 (next step to nuclear war).