India’s security architecture has many layers: the armed forces under the Ministry of Defence, the Central Armed Police Forces (CAPFs) under the Ministry of Home Affairs, State police forces, intelligence agencies, specialised investigation agencies, and the National Security Council system that is meant to tie them together. This chapter maps who does what, under which ministry and law.

What UPSC asks

Mains GS III: the mandate of forces and agencies, coordination gaps, intelligence reform, overuse of CAPFs in internal security duties, police reform, and the role of the Chief of Defence Staff.
Prelims: which ministry controls which force, raising years, statutory versus non-statutory agencies, and the Prakash Singh directions.

Key sub-topics

Layer	Bodies
Armed forces (MoD)	Army, Navy, Air Force; Chief of Defence Staff (2020); Coast Guard
CAPFs (MHA)	Assam Rifles, BSF, CISF, CRPF, ITBP, NSG, SSB
Intelligence	IB, R&AW, NTRO, Defence Intelligence Agency, Multi-Agency Centre
Investigation	CBI, NIA, NCB, ED, DRI
Coordination	National Security Council, NSA, NSCS
Police	State subject; Prakash Singh (2006); Model Police Act (2006)