103. (a) The Federal Government shall be responsible for the protection of every Unit against external invasion and violence.
(b) It shall be the duty of the Governments of Units and Sub-Units to assist the Federal Government in the mobilisation of manpower and resources of the country for the purposes of defence and to maintain communications needed for the purposes of defence.
(c) Whenever a grave emergency exists, whereby the security of India is threatened by war, the Federal Legislature shall have the power to make laws for the Unit so affected or a part thereof even with respect to matters assigned to the exclusive charge of the Unit. Under such circumstances it shall be the duty of all authorities and officials of Units and Sub-Units concerned to co-operate with, and obey instructions of, the Federal Authority, issued for the purposes of the defence of the Republic or a part thereof. The President of the Federation may also take over the charge of the administration of such parts of the Units or Sub-Units as are required for the purposes of the defence of the Republic.