On March 1, 1954, the U.S. conducted its largest nuclear test with a yield of 15 megatons. The new Russian weapon would be up to 100 megatons, according to reports. USAF Lookout Moutain Laboratory hide caption
nuclear weapons nuclear weapons
President Trump and North Korean leader Kim Jong Un are expected to continue to square off in 2018. Evan Vucci, Wong Maye-E/AP hide caption
John Coster-Mullen Meredith Rizzo/NPR hide caption
A Hawaii Civil Defense Warning Device, which sounds an alert siren during natural disasters, is shown in Honolulu on Nov. 29, 2017. The alert system is tested monthly, but now Hawaii residents will hear a new tone designed to alert people of an impending nuclear attack by North Korea. Caleb Jones/AP hide caption
Nuclear Strike Drills Faded Away In The 1980s. It May Be Time To Dust Them Off
A view of Wednesday's successful test launch of the newly developed intercontinental ballistic rocket Hwasong-15 is seen in this undated photo released by North Korea's Korean Central News Agency in Pyongyang. KCNA via Reuters hide caption
South Korean and U.S. marine fighter jets fly over the Korean Peninsula during a training on Aug. 31, 2017 in Gangwon-do, South Korea. Handout/South Korean Defense Ministry hide caption
Secretary of State Rex Tillerson shakes hands with China's President Xi Jinping in Beijing on Saturday. Tillerson acknowledged the U.S. has direct contact with North Korea over its nuclear program. China is seen as crucial in helping to avert a military confrontation. Lintao Zhang/AP hide caption
News of the earthquake in North Korea is reported at the Seoul railway station in South Korea on Saturday. Ahn Young-joon/AP hide caption
A man at a railway station in Seoul watches as North Korean leader Kim Jong Un delivering a statement in Pyongyang. Jung Yeon-je/AFP/Getty Images hide caption
President Trump told the U.N. General Assembly Tuesday that the U.S. may have no choice but to "totally destroy" North Korea if forced to defend itself and its allies. Richard Drew/AP hide caption
Stanislav Petrov, a former Soviet military officer, poses at his home in 2015 near Moscow. In 1983, he was on duty when the Soviet Union's early warning satellite indicated the U.S. had fired nuclear weapons at his country. He suspected, correctly, it was a false alarm and did not immediately send the report up the chain of command. Petrov died at age 77. Pavel Golovkin/AP hide caption
NPR/Ipsos Poll: Half Of Americans Don't Trust Trump On North Korea
People at the Seoul Railway Station in the South Korean capital watch a TV report on North Korea's missile launch on Friday, days after the U.N. Security Council adopted new sanctions against Pyongyang. Chung Sung-Jun/Getty Images hide caption
This picture taken and released on July 4 by an official North Korea news agency shows leader Kim Jong-Un (second from right) inspecting the test firing of a Hwasong-14 ICBM at an undisclosed location. STR/AFP/Getty Images hide caption
Moon Jae-in, South Korea's president, (center) will meet with President Trump on Thursday and Friday. Bloomberg/Bloomberg via Getty Images hide caption