What is unsettling to Kennedy about Khrushchevs public announcement?

Kennedy found Khrushchev's public announcement unsettling because it demonstrated the Soviet leader's willingness to escalate tensions during the Cold War. The announcement revealed the deployment of nuclear missiles in Cuba, which jeopardized U.S. national security and increased the risk of nuclear confrontation. This bold move challenged Kennedy's leadership and forced him to confront the reality of a potential nuclear war in a very public and dangerous standoff.