Core Legal Answer & Context: A Proclamation of National Emergency under Article 352, declared due to war, external aggression, or armed rebellion, profoundly impacts India's federal structure, fundamental rights, and the distribution of legislative and executive powers. It essentially transforms the federal system into a unitary one.

Relevant Statutes and Sections:

1. Article 352: Empowers the President to declare a National Emergency.
2. Article 353: Extends the Union's executive power to direct states and enables Parliament to legislate on State List subjects.
3. Article 354: Allows the President to modify revenue distribution between the Union and States.
4. Article 358: Automatically suspends the fundamental freedoms guaranteed by Article 19.
5. Article 359: Empowers the President to suspend the right to move any court for the enforcement of other Fundamental Rights (except Articles 20 and 21).

Important Landmark Cases:

1. Minerva Mills Ltd. v. Union of India (1980): Emphasized that judicial review of emergency proclamations is not completely barred, though its scope is limited.
2. A.D.M. Jabalpur v. Shivakant Shukla (1976) (Habeas Corpus case): Controversially held that during a 359 proclamation, the right to move court for enforcement of Articles 14, 21, and 22 could be suspended. This was later effectively overturned by the 44th Amendment, which protected Articles 20 and 21 from suspension.

Clear Conclusion: A national emergency under Article 352 centralizes power in the Union, suspends or restricts fundamental rights, and alters the legislative and financial relations between the Union and states, fundamentally changing the constitutional landscape for its duration.