South Korean people watch a television broadcast at the Seoul Railway Station earlier this month reporting North Korea's surface-to-air missile launch. Woohae Cho/Getty Images hide caption

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Castle Romeo was an American hydrogen bomb test in March 1954 at Bikini Atoll in the Pacific. It was 11 megatons, or roughly 1,000 times more powerful than North Korea's test on Wednesday. North Korea says it was a hydrogen bomb test, though the White House says it doubts the claim. Galerie Bilderwelt/Getty Images hide caption

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The U.S. Isn't Buying North Korea's Claim Of An H-Bomb Test
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North Korean leader Kim Jong Un waves during a parade in Pyongyang, North Korea, in October. The country said it carried a successful hydrogen bomb text on Wednesday morning, but many analysts are skeptical. Wong Maye-E/AP hide caption

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Chinese Foreign Minister Wang Yi delivers a speech during the international seminar commemorating the 10th anniversary of the September 19 joint statement of six-party talks at the Diaoyutai State Guesthouse in Beijing, China, on Saturday. Kim Kyung-hoon/Reuters/Landov hide caption

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President Obama listens to Israeli Prime Minister Benjamin Netanyahu during their March 22, 2013, visit to a Holocaust memorial in Jerusalem. Pablo Martinez Monsivais/AP hide caption

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North Korean leader Kim Jong Un, seen here in an undated picture released by the Rodong Sinmun newspaper, has said his country will never give up its nuclear weapons. In the photo, Kim was visiting a hydroelectric power plant. Rodong Sinmun/EPA /LANDOV hide caption

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An Iranian security guard at the Bushehr nuclear power plant in 2010. Iran and negotiators from six world powers are trying to work out a long-term deal on Iran's nuclear program. Vahid Salemi/AP hide caption

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The Stickiest Issues In The Iranian Nuclear Talks
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A Minuteman III intercontinental ballistic missile can hit almost any target on earth ... but only if it flies through Russian airspace. This unarmed test version was launched from Vandenberg Air Force Base in California. V.A. Mouzon/Tech Sgt. Vincent Mouzon/U.S. Air Force hide caption

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Should America Keep Its Aging Nuclear Missiles?
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