Waging war against the Government of India includes terrorists attack motivated by the intention of hitting on the sovereign authority of the Government flooded with powerful explosives and sophisticated arms and ammunitions, irrespective of the number of persons employed to do such activities. The term “Government of India” is a much wider term and is used to mean the Indian State deriving the right and power of authority from the will and consent of its people. The war contemplated by section 121 is not conventional warfare between two nations. Organising or joining an insurrection against the Government of India is also a form of war.
For example, the Mumbai Terror attack on 26 November 2011, the offence committed by the foreign nationals was to accelerate the communal tensions and affect the financial situation of the country; hence they waged war against the Government of India.
The reason is that a citizen owes allegiance to the State by birth or by naturalization and a foreigner by the legal fiction that he resides in India and take the protection of Government of India and hence is subjected to the laws of the land.
It also includes within it the foreigners who enter into Indian Territory with a view to disturb the functioning of the Government and to destabilize the society