The fourth and final Nuclear Security Summit took place in Washington DC from March 31-April 01, 2016. Despite the initial apprehension about the summits in certain parts of the world, it has been a useful process. With more than 50 countries represented from across the world, the summits elevated the level of awareness of nuclear security. Leaders of established nuclear states began to think about nuclear security in a new way, reducing complacency about the risks of terrorism and sabotage. This thinking took shape in national and multilateral commitments in areas including nuclear security regulation, physical protection of nuclear materials, nuclear forensics, protection against nuclear smuggling, and insider threats and nuclear terrorism.