In his book, Natwar Singh has given a very interesting account of the Operation Brasstacks carried out by the Indian army in 1986 and 1987 on the Indo-Pak border.
If Natwar Singh is to be believed then this operation was carried out by Minister of state for defence Arun Singh and Chief of Army Staff Gen Krishnaswamy Sundarji without the knowledge of the then Prime Minister Rajiv Gandhi.
When Rajiv came to know of this, he discussed it with N D Tiwari and Natwar Singh and asked them what to do with his MoS Arun Singh. Natwar singh advised him to sack Arun Singh but Rajiv said,” "Arun Singh is a friend." But a firm Natwar Singh replied, "Sir, you are not the President of the Old Boys' Association of Doon School. You are the Prime Minister of India. Prime Ministers have no friends."