The Nuclear Suppliers’ Group (NSG) is a grouping of 48 nuclear supplier countries to check proliferation of  nuclear weapons based on the guidelines laid down for export of nuclear technology and nuclear related products. The 48 nation group includes the big five nuclear weapon states – US, UK, Russia, France and China. NSG was formed in 1974 after India exploded its nuclear device in Pokhran. Since India was not part of NSG, global concern for nuclear technology development and export by a non-member nation, led to the formation of NSG.