795.00/7–150: Telegram,

The Joint Chiefs of Staff to the Commander in Chief, Far East (MacArthur)

top secret
operational immediate

JCS 84808. 1. In keeping with the United Nations Security Council’s request for support to the Republic of Korea in repelling the Northern Korean invaders and restoring peace in Korea the President announced that he had ordered a Naval blockade of the entire Korean coast.

2. To implement this order you are authorized to use such means and forces as are available to you to deny unauthorized ingress to and egress from the Korean coast. The primary purpose is to suppress seaborne traffic to and from North Korea and to prevent movement by sea of forces and supplies for use in operations against South Korea. Care should be taken to keep well clear of the coastal waters of Manchuria and USSR.

3. Appropriate governmental notification and notice to Mariners will be issued from Washington.1 Advise date measures will be effective.

  1. In a circular telegram transmitted at 7 p. m. on July 3, not printed, the Department of State instructed all diplomatic officers to notify the government to which they were accredited that the naval blockade of the Korean coast was effective immediately (795B.5/7–350).