Can Pakistan challenge Indian strategic depth in the East?

Since the independence of Bangladesh in 1971, the contours of Pakistan’s geopolitical orientation and its engagement with India have changed considerably. India was left sharing only a hostile western border with Pakistan, its eastern border with Bangladesh no longer a security concern. From a geostrategic perspective, this considerably weakened Pakistan’s hand vis a vis India, which was no longer able to threaten India’s eastern border zones and seaboard. India was able to dedicate its military resources against a relatively smaller and weaker foe while enjoying considerable strategic depth in the east. This traditional Indian advantage may no longer remain assured, owing to a range of political and security developments.

The events of 1971 were traumatic for the Pakistani nation, and accepting the newly formed state of Bangladesh was a difficult question. Pakistan’s political elite at the time, led by Prime Minister Zulfikar Ali Bhutto, decided to accept Bangladesh as a new nation under pressure and persuasion from Muslim world leaders. This helped bilateral engagement, but a comprehensive normalization of ties only occurred after the assassination of Sheikh Mujib in a military coup led by General Zia ur Rehman, who assumed power in 1975. Since then the relationship has improved, and was exceptionally cordial during the two governments of Bangladeshi Prime Minister Khaleda Zia, the widow of General Zia, while remaining lukewarm during the first two governments of Sheikh Hasina, the daughter of Sheikh Mujib.

The relationship took a downturn in 2015, during Hasina’s third government, when Pakistan condemned Bangladesh’s execution of Jamaat e Islami leaders for alleged war crimes during the 1971 civil war. The Hasina government reacted strongly, calling it an intrusion into Bangladesh’s internal matters. Around the same time, the newly elected Hindu nationalist government of Prime Minister Narendra Modi in India took particular interest in cultivating a special relationship with Hasina. Ties only began to recover after Hasina’s government was overthrown and she fled to India during the student led July 2024 uprising.

The relationship has since been further complicated by the death sentence handed to Sheikh Hasina by a Dhaka tribunal for crimes against humanity last year. Bangladeshi authorities have approached Delhi to hand her over, but India is unlikely to extradite her to a certain death in Bangladesh. The issue will continue to plague Indo-Bangla ties and any attempts at constructive engagement and trust building between the two sides. The relationship is further strained by Indian attempts to push its Muslim citizens and migrants into Bangladesh.

If Pakistan manages to develop a security foothold near India's eastern borders, the strategic implications would be significant.

-Umar Karim

Against this backdrop, Dhaka is likely to further strengthen its relationship with Pakistan to balance against India, with bilateral security cooperation now emerging as a plank of that partnership. Senior leadership of the Bangladesh Armed Forces has visited Pakistan, most notably the Bangladesh Air Force Chief. India has also alleged that both sides are ramping up intelligence cooperation. This opening of Bangladesh as a security space for Pakistan is a significant development.

After the May 2025 conflict, the Indo-Pakistan relationship remains practically dysfunctional and increasingly securitised. During the conflict, Pakistan successfully targeted Indian defense installations across its western border, but India retained the advantage of strategic depth, with its eastern border remaining secure. If Pakistan manages to develop a security foothold near India’s eastern borders, the strategic implications would be significant. In an interview with The Economist in August last year, Pakistan’s military spokesperson, Lt. Gen. Ahmed Sharif, indicated that in the event of another Indian attack, Pakistan’s response would target deeper inside Indian territory, stating: “We’ll start from the east.” This followed heightened escalation between the nuclear armed neighbors, including India’s Operation Sindoor.

This is where Pakistan’s naval modernization becomes relevant. Pakistan Navy’s surface and subsurface fleet has considerably improved in recent years, most notably with the induction of the Chinese built Hangor class submarines, equipped with an air independent propulsion system that allows them to remain submerged for weeks without surfacing, making detection far more difficult. Once all eight submarines are inducted, the Pakistan Navy will have a combined submarine fleet of 11 boats, posing a critical threat to Indian surface vessels and naval installations. Given the centrality of submarine warfare to Pakistan’s naval doctrine, these subsurface platforms will significantly bolster the navy’s force projection options, including, potentially, toward the east.

Pakistan’s navy has traditionally focused on Anti Access/Area Denial roles, largely in the Arabian Sea, deterring adversaries and protecting sea lines of communication. The Hangor class submarines, built for deeper oceanic waters with higher endurance, could potentially be deployed beyond these traditional areas of operation, opening the possibility of deployment in the Bay of Bengal. Such a development could pose a threat to Indian naval assets on its eastern seaboard, while also overstretching India’s anti-submarine warfare capabilities.

Taken together, evolving political realities in India’s east and the modernization of Pakistan’s submarine fleet may eventually alter the security calculus along India’s eastern borders and seaboard.

Umar Karim is a doctoral researcher at the University of Birmingham. His research focuses on the evolution of Saudi Arabia’s strategic outlook, the Saudi-Iran tussle, conflict in Syria, and the geopolitics of Turkiye, Iran and Pakistan. X: @UmarKarim89