India is shopping for submarines as China extends its reach into the Indian Ocean

The request comes as part of Project 75I, a program worth over $12 billion, according to Defense News.

New Delhi asked shipyards in Russia, France, Japan, and Germany, among others, for information about six submarines equipped with air-independent-propulsion systems, which allow nonnuclear subs to operate without access to atmospheric oxygen, replacing or augmenting diesel-electric systems.

New Delhi is seeking "a proven, effective, state-of-the-art, electric heavyweight torpedo; a land attack missile, and perhaps even an underwater-to-air missile against enemy helicopters and mines," Anil Jai Singh, a retired Indian navy commodore and defense analyst, told Defense News.

Once a response is received from interested shipyards, India will issue a formal request for proposal, then put three or four of the shipyards on a shortlist.

It will be a multiyear process, in part because of New Delhi's Strategic Partner policy, under which a foreign shipyard will be paired with a domestic one in order to compete for the contract.

One contractor told Defense News that the strategic-partner selection should be done by 2019. Another analyst and retired Indian navy officer said it could be "a good seven to eight years after a deal is signed" before the first sub build under the P75I program hits the water.

India's interest in submarines comes as China's growth has increased traffic in the Indian Ocean and through the narrow Malacca Strait connecting it to the waters of East Asia, both above and below the water.

India has been tracking Chinese submarines entering the Indian Ocean since 2013, and a 2015 US Defense Department report confirmed that Chinese attack and missile submarines were operating there.

China has framed its activity in the Indian Ocean and along the African coast as focused on non-military operations, including humanitarian aid, emergency missions, and anti-piracy patrols.

Indeed, the 550-mile-long Malacca Strait, bordered by Indonesia's and Malaysia's jungle shorelines, has become a hotspot for pirates eyeing the 50,000 ships that pass through it each year.

But that activity — coupled with Beijing's growing economic activity in Africa as well as the numerous facilities and alliances it has established along the coast of South Asia — have made India and others wary.

told The Times of India

India has already posted warships near the Malacca Strait to monitor maritime activity and has US-made P-8I Poseidon surveillance planes stationed on the Andaman and Nicobar Islands, an archipelago northwest of the Malacca Strait where India plans to expand its security presence.

The US has agreed to sell New Delhi surveillance drones that could be paired with the Poseidons and used to track Chinese maritime movements in the area — including those of submarines. It is also working to build radar stations on islands in the Indian Ocean and an "undersea wall" of sensors between southern India and northern Indonesia.

China, which is heavily reliant on imported fuel, got about 80% of its oil imports and 11% of natural-gas imports from ships transiting the Malacca Strait. The Tribune of India reported in June that India's activity around the strait was "part of the target given to the Navy to ensure its dominance in the Indian Ocean by 2020."

India's growing focus on submarines and submarine warfare was underscored during the Malabar 2017 naval exercises, conducted with the US and Japan in mid-July. Anti-submarine warfare was one of the exercise's components.

New Delhi's increasing focus on its southern approaches and the broader Indian Ocean come in contrast to centuries of attention paid to security threats at and around its northern boundaries (India and China are currently embroiled in a dispute over territory on the China-Bhutan border.)