Jon B. Wolfsthal is the director of the Nuclear Crisis Group and a senior advisor at Global Zero. He was U.S. President Barack Obama’s special assistant and senior director at the National Security Council for arms control and nonproliferation. He serves on the Science and Security Board of the Bulletin of the Atomic Scientists and helps set the time of the doomsday clock.
Russian Navy Commander in Chief Adm. Vladimir Korolyov, President Vladimir Putin, and Defense Minister Gen. Sergei Shoigu examine a globe in St. Petersburg on July 30, 2017. (Alexey Nikolsky/AFP/Getty Images)
Russian Matryoshka dolls depicting Russian President Vladimir Putin and US President Donald Trump are on sale in the Ruslania book store in Helsinki on July 9. (Timo Jaakonaho/AFP/Getty Images)
A South Korean soldier walks past a television showing U.S. President Donald Trump and North Korean leader Kim Jong Un at a railway station in Seoul on March 9. (Jung Yeon-je/AFP/Getty Images)
Former U.S. President Barack Obama and his counterpart Dmitry Medvedev as they sign the new Strategic Arms Reduction Treaty in Prague on April 8, 2010. (Jewel Samad/AFP/Getty Images)
South Korean soldiers stand guard at a guard post near the Demilitarized Zone (DMZ) dividing two Koreas in the border city of Paju on August 11, 2017.
As nuclear-armed North Korea's missile stand-off with the US escalates, calls are mounting in the South for Seoul to build nuclear weapons of its own to defend itself -- which would complicate the situation even further. / AFP PHOTO / JUNG Yeon-Je (Photo credit should read JUNG YEON-JE/AFP/Getty Images)
This picture taken on July 4, 2017 and released from North Korea's official Korean Central News Agency (KCNA) on July 5, 2017 shows North Korean leader Kim Jong-Un (C) celebrating the successful test-fire of the intercontinental ballistic missile Hwasong-14 at an undisclosed location.
South Korea and the United States fired off missiles on July 5 simulating a precision strike against North Korea's leadership, in response to a landmark ICBM test described by Kim Jong-Un as a gift to "American bastards". / AFP PHOTO / KCNA VIA KNS / STR / South Korea OUT / REPUBLIC OF KOREA OUT ---EDITORS NOTE--- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO/KCNA VIA KNS" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS
THIS PICTURE WAS MADE AVAILABLE BY A THIRD PARTY. AFP CAN NOT INDEPENDENTLY VERIFY THE AUTHENTICITY, LOCATION, DATE AND CONTENT OF THIS IMAGE. THIS PHOTO IS DISTRIBUTED EXACTLY AS RECEIVED BY AFP.
/ (Photo credit should read STR/AFP/Getty Images)
A deactivated Titan II nuclear ICMB is seen in a silo at the Titan Missile Museum on May 12, 2015 in Green Valley, Arizona. The museum is located in a preserved Titan II ICBM launch complex and is devoted to educating visitors about the Cold War and the Titan II missile's contribution as a nuclear deterrent. AFP PHOTO/BRENDAN SMIALOWSKI (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images)
