• Dean Rusk was a senior US government official in charge of Far Eastern Affairs. This was an important job at any time. Clearly it was even more important at the time of the Korean War.
  
• Rusk went on TV and made a long statement about the US policy in Korea. This was quite unusual in 1951.
  
• This document is what is now usually known as a press release. The government created the document to make it easier for the newspapers to quote from Rusk's words. This is common today, but it was a relatively new idea in 1950. This was partly because TV was a relatively new medium.