Union's Duty under Article 355

Article 355 places a constitutional duty on the Union to protect every State against external aggression and internal disturbance. It also requires the Union to ensure that each State government is carried on in accordance with the Constitution.

Nature and scope of the duty

The expression internal disturbance is not defined in the Constitution. It is wider than armed rebellion, the expression used for a national emergency under Article 352, and therefore can cover serious internal disorder that does not reach the emergency threshold.

• Public order ordinarily belongs to the States, but Article 355 makes protection against grave internal disturbance a responsibility of the Union.
• The duty is protective as well as constitutional: it concerns both security within a State and the preservation of constitutional government.

How the Union may discharge it

Article 355 states the Union's duty but does not itself prescribe a single procedure or confer an unrestricted emergency power. Union action must rest on other constitutional or statutory authority and remain subject to judicial review.

• The Union may assist a State through central security forces and other lawful measures appropriate to the situation.
• If an armed rebellion threatens India's security, Article 352 may apply, subject to its safeguards.
• If a State government cannot be carried on according to the Constitution, Article 356 may be invoked, but internal disturbance does not automatically justify President's Rule.

Federal significance

Article 355 balances State responsibility for public order with the Union's obligation to protect the constitutional system. It does not displace elected State governments merely because law and order has deteriorated; the response must satisfy constitutional conditions and federal limitations.