None of these planes will be manufactured in India, and Mr. Modi has not explained how and when the deficit will be made good. Mr. Modi has also failed to explain how jettisoning Hindustan Aeronautics Limited sits with his “Make in India” project to boost manufacturing in India and his promise of ensuring technology transfer in defense manufacturing.

Serious questions have been raised about Mr. Modi approving the purchase of Rafale fighters at an exorbitant cost. The whole package, including maintenance, spares and weapons, was valued at 7.8 billion euros. Experts at India’s defense ministry had estimated that the deal should cost 5.2 billion euros.

A seven-member federal team of military and civilian defense officials was mandated to negotiate weapons prices, delivery schedules, maintenance and other terms of the Rafale deal. Three financial experts on the team supported the lower price benchmark but were outvoted, their objection was ignored, and a higher level body increased the benchmark. The final higher price was ratified by the Cabinet Committee for Security, led by Mr. Modi.

In my reporting, I also found that Mr. Modi’s arbitrary decision to reduce the number of Rafale planes purchased to 36 from 126 raised the price of each plane by 41 percent over the price quoted by Dassault in 2007 and 14 percent over the 2011 price that factored in escalation costs.

Dassault Aviation sought an exorbitant fixed cost of 1.3 billion euros for “design and development” of 13 India-specific enhancements of the Rafale fighters. Despite objections from three members of the team, the Indian government accepted the demand and the consequent inflation in the cost of the Rafale fighters.

In July 2014, the Eurofighter Typhoon Consortium, which had lost the original bid, made a new offer with a 20 percent discount. The dissenting experts wanted Mr. Modi’s government to consider it, but the prime minister had already spoken his mind and the idea was discarded.

Had Mr. Modi heeded the dissenters, India could have saved about 2.6 billion euros — a sum that is significant for a country where tens of millions are deprived of a living wage, nutrition, schooling and health care. Saving even two billion euros on a weapons deal could easily go toward building several thousand schools and hospitals in India’s villages.