The Nuclear Command Authority (NCA) of India is the authority responsible for command, control and operational decisions regarding India's nuclear weapons programme. It comprises a Political Council headed by the Prime Minister of India and an Executive Council headed by the National Security Advisor. Introduction India's first Nuclear test was conducted on 18 May 1974 with the code name Smiling Buddha. Since then India has conducted another series of tests at the Pokhran test range in the state of Rajasthan in 1998, which included a thermonuclear test, code named Operation Shakti. India has an extensive civil and military nuclear program, which includes at least 10 nuclear reactors, uranium mining and milling sites, heavy water production facilities, a uranium enrichment plant, fuel fabrication facilities, and extensive nuclear research capabilities. Though India has not made any official statements about the size of its nuclear arsenal, different country estimates indicate that India has anywhere between 150 and 300 nuclear weapons. On 4 January 2003, the Cabinet Committee on Security (CCS) constituted the Political Council and the Executive Council of the NCA. The Executive Council gives its opinion to the Political Council, which authorises a nuclear attack when deemed necessary. While the Executive Council is chaired by the National Security Advisor (NSA), the Political Council is chaired by the Prime Minister. This mechanism was implemented to ensure that Indian nukes remain firmly in civilian control and that there exists a sophisticated Command and Control (C2) mechanism to prevent their accidental or unauthorised use. Strategic Forces Command The directives of the NCA are to be operationalised by the Strategic Forces Command under the control of a Commander-in-Chief of the rank of either of the three tri-service high ranks in charge of the management and administration of the tactical and strategic nuclear forces. The NCA may be seen as the first stage in the development of an effective and robust Command and Control (C2) and Indications-and-Warning (I&W) systems and infrastructure for its strategic nuclear forces. Delivery of weapons The current status of delivery systems for Indian nuclear weapons is unclear and highly classified. India has developed and tested nuclear weapons that could be delivered on the Prithvi and Agni missiles, although its extent and operational preparedness in this respect remains unclear. India first tested the 150 km range Prithvi-1 in 1988, and the 250 km range Prithvi-2 in 1996, and the Prithvi missiles were inducted into