Secretary General of the Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) Lassina Zerbo gestures during an interview with Reuters in Vienna May 9, 2014. Zerbo, a ... more 
Secretary General of the Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) Lassina Zerbo gestures during an interview with Reuters in Vienna May 9, 2014. Zerbo, a geophysicist from Burkina Faso who took office last year, called on countries which have yet to ratify the test ban treaty to do so in order for it to finally become international law. There is widespread international support for the pact, which has been ratified by more than 160 states, but it cannot come into effect because some nuclear powers like the United States and China have not yet taken that step. To match story NORTHKOREA-NUCLEAR/CTBTO Picture taken May 9, 2014. REUTERS/Leonhard Foeger (AUSTRIA - Tags: POLITICS) less 
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Reuters | Photo By LEONHARD FOEGER / REUTERS
Fri, May 9, 2014 9:52 AM EDT