Gloria Steinem and South Korean peace activists march along a military fence at a checkpoint after crossing the border separating North and South Korea. Jung Yeon-Je/AFP/Getty Images hide caption

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South Korean Foreign Minister Yun Byung-se and U.S. Secretary of State John Kerry hold a joint news conference following meetings at the Ministry of Foreign Affairs in Seoul. Saul Loeb/AFP/Getty Images hide caption

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A man watches a television showing news coverage of the reported execution of North Korea's defense minister, Hyon Yong Chol, at a railway station in Seoul on Wednesday. Ed Jones/AFP/Getty Images hide caption

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An image obtained by Yonhap News Agency showing North Korean leader Kim Jong Un pointing at a ballistic missile believed to have been launched from underwater near Sinpo, on the northeast coast of North Korea, on Saturday. KCNA/EPA/Landov hide caption

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North Korean defector Shin Dong-hyuk came to prominence in a 2012 book about his life in a North Korean prisoner camp. He now says some key parts of his story were not true. His case highlights the difficulty in confirming information in a closed society like North Korea. Chip Somodevilla/Getty Images hide caption

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Amid much speculation by private security analysts, the FBI stood by its claim this week that North Korea was responsible for the hack against Sony Pictures. Damian Dovarganes/AP hide caption

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