Context:

• General Bipin Rawat taking over as the first Chief of Defence Staff (CDS) on New Year’s Day, a new structure is being created in the Defence Ministry. 

The dual-hatted role:

• The dual-hatted role refers to the two hats the CDS wears: one of the permanent Chairman of the Chiefs of Staff Committee which has the three service chiefs as members, and the other of the head of the newly created Department of Military Affairs (DMA) in the ministry. 
• The former is a military role while the latter is a role in the government.

The Army, the Navy and the Air Force — not departments of the ministry:

• The Army, the Navy and the Air Force used to come under the Department of Defence so far, but will now fall under the ambit of DMA, and will have an appropriate mix of civilian and military officers at every level.
• Attached offices are generally responsible for providing executive direction required in implementation of policies laid down by the department to which they are attached, in this case now the DMA.

Working:

• CDS acts the Principal Military Adviser to the Defence Minister only on tri-services matters. In fact, the three service chiefs will continue to advise the Defence Minister, as done so far, on matters exclusively concerning their respective services. 
• CDS will not exercise any military command, including over the three service chiefs.
• The service chiefs will be members of the Chiefs of Staff Committee, which will be headed by the CDS.

Conclusion:

• The Department of Defence — headed by the Defence Secretary — will be responsible for the “defence of India and every part thereof, including defence policy and preparation for defence and all such acts as may be conducive in times of war to its prosecution and after its termination to effective demobilisation”.