Why is India building a military base on Agaléga island?

New Delhi is seeking to expand its presence in the Indian Ocean to challenge Chinese expansionism.

On August 3, Al Jazeera published an extensive investigation into the development of a military facility on North Agaléga island, which is part of the island nation of Mauritius. It revealed that Indian workers are laying the groundwork for what is expected to be an Indian naval military facility.

Although both the Mauritian and Indian governments are denying it, documents and witness accounts Al Jazeera has obtained indicate the construction of various infrastructure purposed for military activities, especially surveillance.

India asserts that these new facilities are part of its Security and Growth for All in the Region (SAGAR) policy, which aims to increase maritime cooperation between countries in the region. Mauritius, for its part, has indicated that its coastguard personnel will use the new facilities.

But it is clear that the Indian investment of $250m in developing an airfield, port, and communications hub on this remote island is not aimed at helping Mauritius develop its capacity to police its territorial waters.

North and South Agaléga islands, which are home to approximately 300 ethnically Creole Agaléens, are located in the strategically important southwestern part of the Indian Ocean. The area is currently a blind spot for the Indian Navy and by building a military facility in it, New Delhi hopes to expand its maritime domain awareness.

The most important new infrastructure on the atoll is a 3,000-metre runway, and considerable apron for aircraft. Under construction also are sizable jetty facilities in deeper water, and what looks like barracks and fields which could be used by military personnel.

The outpost at Agaléga will be useful to support the operation of India’s fleet of Boeing P-8I maritime surveillance aircraft. The US-made P-8, based on the Boeing 737 passenger aircraft, is a cutting-edge maritime patrol aircraft, tasked with anti-submarine warfare, anti-surface warfare, and intelligence, surveillance and reconnaissance missions.

While these aircraft have an anti-shipping and submarine strike function, their peace-time utility is derived from the sophisticated sensors, command and control systems, radars, and intelligence-gathering equipment utilised on routine missions.

The vastness of the Indian Ocean means that P-8s and other maritime surveillance aircraft require airfields and refuelling facilities at staging points, which is where facilities like those on North Agaléga island come in.

And Agaléga is not the only Indian Ocean island modified for P-8 use. For instance, military facilities on India’s Andaman and Nicobar Islands in the northeastern Indian Ocean, at the junction of the Bay of Bengal and the Andaman Sea, were also enhanced to better support India’s patrol aircraft missions.

In peace time, effective maritime domain awareness helps establish international partnerships with like-minded militaries and also acts as a deterrent to both state and non-state adversaries, by signalling reach and an intention to safeguard interests in a selected area. By better understanding existing and incoming maritime threats, a government can better plan and respond.

In times of conflict, knowing the location of enemy ships and submarines, without being detected in the process, creates a significant advantage.

While India may publicly justify its effort and expense to build maritime domain awareness in the Indian Ocean with combatting piracy, developing search and rescue capabilities or even providing small states with capacity-building assistance, China’s naval forays into this region is the true motivator for its expanding naval presence.

The Indian Ocean is now increasingly contested. Despite its Diego Garcia base, the United States no longer enjoys predominance in this increasingly multipolar region – in which no one power wields hegemonic influence.

In recent years, China has increased naval deployments into the Indian Ocean, developed what some analysts call a “string of pearls” – a network of military and commercial facilities along the Indian Ocean littorals, effectively encircling India – and even established its first overseas naval base in Djibouti.

Given China’s recent Indian Ocean deployments, its vast military modernisation programme, its recent conduct on the India-China Himalayan border, and its demonstration of coercive statecraft on the international stage in general, India is logically eager to inhibit Chinese naval presence in the Indian Ocean.

As a result, India – in coordination with the United States, Australia and even France – is undertaking efforts to surveil the Indian Ocean to directly deter and limit China’s ability to operate in this region.

The southwestern part of the ocean, in particular, is of increasing strategic importance due to economically vital shipping routes passing through the Mozambique Channel and around southern Africa, which China also uses for its energy imports.

In this sense, the facilities at Agaléga would enable India to keep an eye on this part of the ocean and will constitute a key staging post in the Indian maritime domain awareness network. It is important insofar as it will enable Indian eyes in the sky across the southwest Indian Ocean, which policymakers in Delhi hope will restrain Chinese encroachment.

Time will tell exactly how India will make use of these facilities on Agaléga once completed later this year. Project specifics are still being tightly held by both the Indian and Mauritian governments.

Whether or not China is deterred by India’s surveillance efforts, Agaléga is now a pawn in this new era of major power competition across the Indian Ocean and indeed the wider Indo-Pacific region.

The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial stance.