The Nuclear Security Summit (NSS) was a semi-annual world summit, aimed at preventing nuclear terrorism around the globe. The first summit was held in Washington, D.C., United States, on April 12–13, 2010. The second summit was held in Seoul, South Korea, in 2012. The third summit was held in The Hague, Netherlands, on March 24–25, 2014. The fourth and final summit was held in Washington, D.C., on March 31–April 1, 2016.[1]