India conducted five nuclear tests of advanced weapon designs between May 11 and 13 at Rajasthan's Pokhran desert that propelled the country into a select group of nations having capabilities to develop nuclear weapons. The tests, carried out during the then Atal Bihari Vajpayee-led government, were the culmination of a committed team effort and backed by the development of the necessary know-how and expertise over decades. The tests triggered strong reactions from many countries. India maintained that it carried out the tests to have 'credible minimum deterrence' and it will follow the approach of "no first use", noting that it would not be the first one to launch a nuclear weapon. In 2003, India officially came out with its nuclear doctrine that clearly elaborated on the 'no first use' policy. 

Read our coverage on India's historic moment 25 years ago here.