KUWAIT CITY, KUWAIT - DECEMBER 13: Czech soldiers in chemical protection suits take part in a chemical attack response drill conducted at the U.S. Embassy by civil defense authorities and troops from the United States, Germany, and Czech Republic December 13, 2002 in Kuwait City, Kuwait. The exercise, dubbed 'Event Horizon,' was staged to test the coordinated emergency response to a mock attack on the U.S. Embassy in Kuwait by terrorists using deadly sarin nerve gas.
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What are nerve agents like Novichok and how do they kill?
Novichok, a highly poisonous chemical, was designed by Russia during the Cold War and made to be undetectable by standard detection equipment. CNN explores how it, and other nerve agents, work.
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KUWAIT CITY, KUWAIT - DECEMBER 13: Czech soldiers in chemical protection suits take part in a chemical attack response drill conducted at the U.S. Embassy by civil defense authorities and troops from the United States, Germany, and Czech Republic December 13, 2002 in Kuwait City, Kuwait. The exercise, dubbed 'Event Horizon,' was staged to test the coordinated emergency response to a mock attack on the U.S. Embassy in Kuwait by terrorists using deadly sarin nerve gas.
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What are nerve agents like Novichok and how do they kill?
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US President Donald Trump addresses the nation on the situation in Syria April 13, 2018 at the White House in Washington, DC. Trump said strikes on Syria are under way. / AFP PHOTO / Mandel NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)
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