The National Security Act, 1980 (NSA) is an Act of the Indian Parliament, enacted on December 27, 1980, with the primary purpose of providing for preventive detention in certain cases and matters connected therewith. The Act extends to the whole of India. Its origin lies in a history of similar laws, succeeding the controversial Maintenance of Internal Security Act (MISA), 1971, which was repealed in 1977. The NSA was promulgated during the Indira Gandhi government to fill the gap left by MISA's repeal, addressing perceived threats to national security and public order.
The core mechanism of the NSA is the power of preventive detention, which allows the Central or State Governments to detain a person to prevent them from acting in any manner prejudicial to the defence of India, the security of India, the relations of India with foreign powers, the maintenance of public order, or the maintenance of supplies and services essential to the community. This power is outlined in Section 3 of the Act. A person can be detained for a maximum period of 12 months without formal charges or trial. Crucially, this detention is preventive, not punitive, meaning it is based on suspicion of future actions rather than punishment for a past crime.
The Act connects directly to Article 22 of the Constitution of India, which permits laws for preventive detention while also laying down certain safeguards. A key procedural safeguard is the requirement under Section 9 to constitute an Advisory Board—comprising persons who are or are qualified to be High Court judges—to review the detention order. The government must refer the case to the Advisory Board within three weeks of the detention order. The NSA has been amended several times, including by the National Security (Amendment) Act, 1984 and the National Security (Second Amendment) Act, 1984, which notably inserted Section 5A to ensure that grounds of detention are severable. The Act remains in force and has not been replaced, though its application and constitutional validity are frequently subject to judicial scrutiny and public debate due to its suspension of standard legal rights like the right to legal counsel during the Advisory Board review.