Seoul: President Park Chung-hee declares a state of emergency in South Korea, citing a threatened invasion by North Korea. The move drastically curtails freedom of speech, thus helping him tighten his grip on power. According to Yonhap News Agency, in 1979, the nation's electoral college, called the National Conference for Unification, picked interim leader Choi Kyu-hah as president. He filled the political vacuum created by the assassination of President Park Chung-hee at the hands of his intelligence chief, Kim Jae-kyu. In 1994, a North Korean government delegation arrived in Washington for talks on improving ties between the two former battlefield foes, including a suggestion to establish liaison offices. It was the North's first official delegation to visit the United States. In 2003, President Roh Moo-hyun promulgated a law that called for the appointment of an independent counsel to probe allegations that his former aides took bribes. In 2007, U.S. President George Bush sent a letter to North Korean leader Kim Jong-il as Washington worked to secure a complete list of North Korea's nuclear programs. In 2008, North Korea announced it would not speak to Japan in the six-party nuclear talks, with Tokyo refusing to provide its share of promised energy for Pyongyang. In 2012, the International Olympic Committee opened an investigation into a South Korean footballer's politically charged celebration of the country's bronze medal at the London Olympics. Midfielder Park Jong-woo celebrated South Korea's 2-0 win over Japan in the bronze medal match with a sign that read, in Korean, "Dokdo Is Our Territory." It was in support of South Korea's sovereignty over its easternmost islets, to which Japan has also laid claim for years. In 2022, North Korea fired a barrage of artillery shells into a maritime buffer zone for the second consecutive day in response to live-fire drills between South Korea and the United States.