Explained: how India and Pakistan became nuclear states

India and Pakistan announced their arrivals as nuclear powers with a flurry of weapons testing in 1998. The two countries have since refrained from testing their nukes but have nevertheless been generally accepted as de facto nuclear states and continued to invest heavily in their respective nuclear capacities.Neither is party to the Treaty on Non-Proliferation of Nuclear Weapons (NPT), the arms control agreement signed by 189 other nations. In exchange for access to peaceful uses of nuclear…