India Pakistan War, 1971: The war that cut Pakistan by Half forever

The India Pakistan War of 1971 was the third battle fought between India and Pakistan.  It occurred during the Bangladesh Liberation War in East Pakistan. The war lasted 13 days from 03 December 1971 to 16 dec 1971. The war ended with Eastern Command of Pakistan signing Instrument of Surrender on 16 Dec 1971 in Dhaka.  During the war, the Prime minister of India was Smt Indira Gandhi and Army Chief Was General Sam Manekshaw. The Air Force chief was Air Chief Marshal Pratap Chandra Lal and the Navy chief was Admiral Sardarilal M Nanda.

Tensions in East Pakistan

The Indo-Pakistani conflict stemmed from tensions between East and West Pakistan, rooted in the 1947 partition of India, political struggles, and ethnic differences. The situation worsened with events like the 1950 language movement, 1964 riots, and 1969 protests, leading to President Ayub Khan’s resignation and General Yahya Khan’s assumption of power. In 1970, the Awami League’s Sheikh Mujibur Rahman gained a major victory in the general elections, which heightened fears in West Pakistan about Bengali dominance.

Despite attempts to resolve the crisis through the Admiral Ahsan Mission, political tensions remained. The military’s veto of the mission’s proposal, Zulfikar Ali Bhutto’s opposition, and the refusal to allow Mujibur Rahman to govern led to strikes and ethnic violence. The Pakistani military cracked down on East Pakistan in March 1971, and mass arrests followed. The “Bihari massacre” in Chittagong provided a pretext for military action. On March 26, 1971, Major Ziaur Rahman declared Bangladesh’s independence.

In response, the Mukti Bahini (Bangladesh Liberation Army) formed, and an exiled government was set up. Tensions escalated as India supported the rebellion, and in November 1971, Prime Minister Indira Gandhi rejected US advice to avoid intervention.

India Pakistan War, 1971: Conditions that lead to war

By the end of April 1971, Prime Minister Indira Gandhi had asked India’s Chief of Army Staff, General Sam Manekshaw, if he was prepared to go to war with Pakistan. According to Manekshaw’s own account, he declined, citing the arrival of the monsoon season in East Pakistan and the ongoing refitting of army tanks. He offered his resignation, but Gandhi refused to accept it. He then guaranteed victory, provided she allowed him to prepare for the conflict on his own terms and set the date for it, which Gandhi agreed to.

By mid-July, India had developed a plan of attack. The ground in the East would be drier by mid-November, making a rapid offensive more feasible. By early to mid-December, the Himalayan passes would be closed by snow, preventing China from intervening.

In Pakistan, the media’s tone had become increasingly jingoistic and militaristic, particularly regarding East Pakistan and India. Despite mixed reactions among pundits, by the end of September 1971, a propaganda campaign—possibly backed by elements within the Pakistani government—led to “Crush India” stickers becoming a common sight on vehicles in Rawalpindi, Islamabad, and Lahore, eventually spreading to the rest of West Pakistan. By October, other stickers calling for the execution of Sheikh Mujibur Rahman, referring to him as a “Traitor,” began to appear.

Between mid-October and 20 November, the Indian army made several incursions into East Pakistani territory, typically withdrawing to India after completing their missions. However, on 21 November, Indian forces, supported by Mukti Bahini, entered East Pakistan and stayed there, preparing for a formal war that India expected to begin on 6 December.

An Indian-Pakistani war seemed imminent. The Soviet Union reportedly cautioned Pakistan against going to war, describing it as a “suicidal course for Pakistan’s unity.” Despite this warning, in November 1971, thousands of people, led by conservative Pakistani politicians, marched in Lahore and across the country, calling for Pakistan to “crush India.” On 23 November, President Yahya Khan declared a national state of emergency and instructed the nation to prepare for war. By the first week of December, conservative print media outlets had published jihad-related materials to encourage military recruitment.

Declaration of War 

On the evening of 3 December, at approximately 17:35, the Pakistan Air Force (PAF) launched surprise preemptive strikes on eight Indian airfields, including Agra, which was located 480 kilometers (300 miles) from the border. At the time of the attack, the Taj Mahal had been camouflaged with twigs, leaves, and burlap to hide its prominent glow in the moonlight. These preemptive strikes, known as Operation Chengiz Khan, were inspired by the success of Israel’s Operation Focus during the 1967 Arab–Israeli Six-Day War. However, unlike the Israeli attack on Arab airbases, which involved a large number of planes, Pakistan deployed too few aircraft to cause significant damage.

Later that evening, Prime Minister Indira Gandhi addressed the nation via radio, declaring the air strikes to be a formal declaration of war against India. In response, the Indian Air Force (IAF) carried out initial air strikes that same night, followed by massive retaliatory air strikes the next morning.

This airstrike marked the beginning of full-scale war. Gandhi ordered the mobilization of troops and initiated a comprehensive invasion of East Pakistan, involving coordinated air, sea, and land assaults. The primary objective for India on the eastern front was to capture Dacca, while on the western front, the goal was to contain Pakistani forces.

Ground Operations

The Indian army was better equipped and had a significant numerical advantage over the Pakistani forces.

Pakistan initiated a ground offensive on the western front, concentrating major attacks along the western border. While the Pakistani Army launched these assaults, the Indian Army successfully penetrated Pakistani territory, gaining about 15,010 km² (5,795 sq mi) of land in Azad Kashmir, Punjab, and Sindh. This territory was later ceded to Pakistan in the 1972 Simla Agreement as a gesture of goodwill.

The Pakistan Army’s I Corps, II Corps, and the Pakistan Marines’ Punjab detachment suffered heavy casualties, largely due to poor operational planning and lack of coordination between the army and marine units. As a result, many soldiers and marines were demoralized and lacked the will to resist the advancing Indian forces.

Western Front

Battle of Hussainiwala

On 3 December, following the Pakistan Air Force’s airstrike, the Pakistani 106 Infantry Brigade, commanded by Brigadier Mohammad Mumtaz Khan, advanced towards Hussainiwala with 2,000 troops and artillery support. The Indian forces, led by Lt. Col. Shastry of the 15 Punjab Battalion, had only 900 soldiers and air support. Despite efforts to hold the village, the Indian forces were forced to retreat by 4 December towards the Kaiser-i-Hind fortress. The Pakistani forces pushed them out, resulting in 125 Indian casualties and 67 Pakistani casualties.

Battle on Chhamb

At the same time, Pakistani forces launched an offensive in Chhamb, reminiscent of the 1965 Indo-Pakistani War. Pakistani 23 Armoured Division, under Major General Iftikhar Janjua, advanced against the Indian 10 Division, commanded by Major General Jaswant Singh. The Pakistani forces made initial progress, but by 9 December, Major General Janjua was killed, and by 11 December, Indian forces had pushed them back. The territory gained by Pakistan in this battle was retained after the Simla Agreement. Chhamb was lost by India.

Battle on Longewala

On 4 December, a Pakistani unit from the 18 Infantry Division, commanded by Major General B. M. Mustafa, advanced towards the Rajasthan town of Longewala, which was defended by an understrength Indian company. Despite the Indian forces being outnumbered, they held their ground with heavy air support and anti-tank defenses. The Pakistani armored advance was stalled, and the Indian Air Force played a significant role in repelling the attack. The Battle of Longewala ended in a decisive Indian victory by 7 December.

Battle of Basantar

Pakistan’s I Corps attempted to disrupt Indian supply lines in the Shakargarh sector by advancing on 6 December. Despite their numerical advantage, Pakistani forces failed to capture the region and were pushed back by the Indian I Corps, which eventually threatened Sialkot. This battle, known as the Battle of Basantar, ended in an Indian victory.

Between 8 and 14 December, India captured an 800 km² stretch of the Karakoram range in the Ladakh region during the Battle of Turtuk.

Eastern Front

The conflict in the East quickly turned in favor of India and its Bengali allies, both militarily and diplomatically. Even before the formal declaration of war, India began operations on 23 November, crossing into East Pakistan and joining forces with Bengali nationalists. Unlike the slow-paced battles of 1965, India adopted a rapid, three-pronged attack with nine infantry divisions, armored units, and air support, all converging on Dacca, the capital of East Pakistan.

Led by Lieutenant General Jagjit Singh Aurora, the Indian forces quickly overwhelmed Pakistani positions. The Indian Air Force destroyed Pakistan’s small air contingent in East Pakistan, rendering Dacca’s airfield unusable, while the Indian Navy effectively blockaded the region.

The Indian Army’s swift “blitzkrieg” tactics exploited Pakistani weaknesses, bypassing their defenses and leading to a rapid collapse. Facing devastating losses, the Pakistani military in the East was unable to mount any meaningful resistance. On 16 December, the Indian Army encircled Dacca and issued an ultimatum for surrender. Lieutenant General A.A.K. Niazi, the commander of Pakistan’s Eastern Command, surrendered without resistance, and the Pakistani government collapsed. Pakistan called for a unilateral ceasefire, and its entire military in East Pakistan surrendered, bringing the war to an end.

The ground war resulted in significant casualties: Pakistan suffered around 8,000 dead and 25,000 wounded, while India lost 3,000 soldiers and had 12,000 wounded. The disparity in armored vehicle losses also highlighted Pakistan’s defeat, marking a major military setback for the country.

The performance of the Indian Army, especially after its defeat in the 1962 Sino-Indian War, significantly boosted its morale and prestige.

Naval Operations

In the 1971 war, the Pakistani submarine PNS Ghazi sank off the fairway buoy near Visakhapatnam on India’s eastern coast, marking the first submarine loss in the waters around the Indian subcontinent.

The Indian Navy imposed a blockade on Pakistan’s trade and supply lines in the Bay of Bengal, particularly in the eastern theater. Meanwhile, the Indian Air Force carried out bombing raids on various towns and cities in East Pakistan. Pakistani naval leaders were well aware that, unlike the 1965 war, their Navy was ill-prepared for a conflict with India. The Pakistan Navy was unable to launch an offensive in deep water or mount a serious defense against India’s seaborne incursions.

Operation Trident

In the western theater, the Indian Navy’s Western Naval Command, under Vice Admiral S.N. Kohli, launched a surprise attack on Karachi’s port on the night of 4/5 December 1971, under the codename Trident. The attack involved Soviet-built Osa-class missile boats and resulted in the sinking of the Pakistan Navy’s destroyer PNS Khaibar and minesweeper PNS Muhafiz, while the PNS Shah Jahan was heavily damaged.

The attack led to the death or injury of around 720 Pakistani sailors, significant fuel reserves were destroyed, and numerous commercial ships were lost, severely crippling the Pakistan Navy’s further involvement in the conflict. In retaliation, Pakistan’s submarines targeted major Indian warships, and on 9 December, the submarine PNS Hangor sank the INS Khukri, killing 194 Indian sailors. This marked the first submarine kill since World War II.

Operation Python

On the night of 8/9 December, the Indian Navy launched another attack on Karachi under the codename Python. A squadron of Indian Osa missile boats launched Styx missiles, causing further destruction to Pakistani fuel reserves and sinking three Pakistani merchant ships, along with foreign vessels docked at Karachi. Meanwhile, Pakistan’s air force mistakenly attacked its own ship, PNS Zulfiqar, after misidentifying it, causing major damage and casualties among the crew.

Eastern Front : Blockade of East Pakistan

In the eastern theater, the Indian Navy’s Eastern Naval Command, under Vice Admiral Nilakanta Krishnan, implemented a naval blockade of East Pakistan, effectively trapping the Eastern Pakistani Navy and eight foreign merchant vessels. From 4 December onwards, the Indian aircraft carrier INS Vikrant, with its Sea Hawk fighter-bombers, launched strikes on coastal towns, including Chittagong and Cox’s Bazar.

In response, Pakistan sent the submarine PNS Ghazi to challenge the blockade, but it sank off Visakhapatnam due to an internal explosion. It remains unclear whether the explosion was caused by Indian depth charges or another factor.

Facing defections and severe operational challenges, Pakistan relied on its Marines, under Rear Admiral Leslie Mungavin, to conduct riverine operations against the Indian Army in East Pakistan. However, these operations were poorly executed due to the Marines’ lack of experience in expeditionary warfare and the challenging terrain, resulting in heavy losses.

The Pakistan Navy’s losses during the conflict included 7 gunboats, 1 minesweeper, 1 submarine, 2 destroyers, 3 patrol crafts from the Pakistan Coast Guard, 18 cargo and supply vessels, and significant damage to Karachi’s naval base and docks. Additionally, three merchant ships—Anwar Baksh, Pasni, and Madhumathi—along with ten smaller vessels, were captured. In total, around 1,900 Pakistani personnel were killed, and 1,413 were captured in Dacca. According to Pakistani scholar Tariq Ali, the country lost half of its navy in the war.

Air Operations

Following the attempted preemptive strike, the Pakistan Air Force (PAF) adopted a defensive posture in response to India’s retaliation. As the war progressed, the Indian Air Force (IAF) continued engaging the PAF over various conflict zones, but the PAF’s sorties dwindled each day. While the IAF flew 4,000 sorties, the PAF’s response was limited, partly due to a shortage of non-Bengali technical personnel.

This limited retaliation was also attributed to a deliberate decision by the PAF’s Air Headquarters (AHQ) to minimize further losses, having already suffered significant casualties during the conflict in East Pakistan. The PAF refrained from engaging with the Indian Navy after its raids on Karachi but retaliated by bombing Okha harbor, destroying fuel tanks used by the boats that had attacked.

In the eastern theater, No. 14 Squadron “Tail Choppers” was wiped out, and its commanding officer, Squadron Leader PQ Mehdi, was captured, effectively neutralizing Pakistan’s air command in Dhaka. This allowed India to establish complete air superiority on the eastern front.

By the end of the war, several PAF pilots managed to escape East Pakistan, fleeing to neighboring Burma. Many PAF personnel had already fled to Burma before Dacca fell to Indian forces in December 1971.

Indian Attacks on Pakistan

As the Indian Army consolidated its position in East Pakistan, the Indian Air Force (IAF) continued its air assaults on Pakistan, shifting to a pattern of daylight strikes targeting airfields, radar installations, and providing close support with fighter jets. At night, the IAF launched attacks on airfields and strategic targets using Canberras and An-12s. In response, Pakistan conducted similar night missions with its B-57s and C-130s.

The Pakistan Air Force (PAF) primarily deployed its F-6s for defensive air patrols over their own bases, limiting their ability to conduct effective offensive operations. During these raids, the IAF damaged a USAF aircraft and a UN plane in Dacca, while a RCAF DHC-4 Caribou was destroyed in Islamabad, along with a USAF Beech U-8, which belonged to Brigadier-General Chuck Yeager, the US military’s liaison chief. The IAF continued sporadic raids on PAF forward air bases in Pakistan throughout the war, maintaining interdiction and close-support missions.

One of India’s most successful air strikes occurred on December 8, 1971, when Indian Hunter jets from the 20 Squadron, based in Pathankot, attacked the Pakistani base in Murid, destroying five F-86 aircraft on the ground. This was confirmed by Pakistan’s military historian, Air Commodore M. Kaiser Tufail, in his book In The Ring and on Its Feet: Pakistan Air Force in the 1971 Indo-Pak War.

The PAF’s role in the air campaign was more limited. They were reinforced by Mirages from an unidentified Middle Eastern ally, with reports suggesting that Libyan F-5s were deployed to Sargodha Air Base, possibly to train Pakistani pilots in anticipation of more F-5s from Saudi Arabia. The IAF, however, carried out a broad range of missions, including troop support, air combat, deep strikes, para-dropping behind enemy lines, feints to divert enemy fighters, bombing, and reconnaissance. Meanwhile, the PAF, which was focused solely on air combat, was largely overwhelmed within the first week of the conflict. Surviving PAF aircraft either took refuge at Iranian airbases or hid in bunkers, avoiding further combat.

India flew 1,978 sorties over East Pakistan and about 4,000 over Pakistan, while the PAF completed approximately 30 sorties in the East and 2,840 in Pakistan. By the end of the war, India had lost 45 aircraft, while Pakistan lost 75.

Surrender of Pakistan Eastern Command

The official Instrument of Surrender for the Pakistan Eastern Command stationed in East Pakistan was signed at 16:31 IST on December 16, 1971, at the Ramna Race Course in Dacca. The signatories were Lieutenant General Jagjit Singh Aurora, the General Officer Commanding-in-Chief of the Indian Eastern Command, and Lieutenant General A.A.K. Niazi, the Commander of the Pakistan Eastern Command.

As the surrender was accepted quietly by Lieutenant General Aurora, the surrounding crowds at the racecourse began chanting anti-Pakistan slogans, and there were reports of verbal abuse directed at the Pakistani military commanders. Indian officers and an Indian diplomat, AK Ray, the joint secretary for Pakistan at India’s Ministry of External Affairs, had to form a human chain around Lieutenant General Niazi to protect him from being attacked by the angry crowd.

Hostilities officially ceased at 14:30 GMT on December 17, 1971, following the surrender the previous day. While India claimed significant territorial gains, the pre-war boundaries were eventually restored after the war. The outcome confirmed the independence of Bangladesh.

After the surrender, the Indian Army took approximately 90,000 Pakistani soldiers and their Bengali supporters as prisoners of war, marking the largest surrender since World War II. Initial reports estimated that about 79,676 of the POWs were military personnel, with the majority being officers, particularly from the army and navy, while smaller numbers came from the air force and marines. Additionally, a substantial number were paramilitary units.

The remaining prisoners consisted of civilians, including family members of military personnel and volunteers (razakars). According to the Hamoodur Rahman Commission and the POW Investigation Commission reports, it was estimated that around 15,000 Bengali civilians were also taken as prisoners of war.

Foreign Reactions and Involvement

United States and Soviet Union

The Soviet Union sympathized with the East Pakistanis and supported India’s military actions alongside the Mukti Bahini against Pakistan. This was part of a broader strategy to weaken the influence of its rivals, the United States and China, by backing the secession of East Pakistan and the formation of an independent Bangladesh. The Soviet Union assured India that it would provide support if a confrontation with the United States or China occurred, an assurance formalized in the Indo-Soviet Treaty of Friendship and Cooperation signed in August 1971.

While the Soviet Union backed India’s stance on East Pakistan’s resolution, it did not fully align with all of India’s positions, according to author Robert Jackson. Up until mid-October 1971, the Soviet Union continued offering economic aid to Pakistan and extended some gestures of support. In November 1971, Soviet Ambassador to Pakistan, Alexei Rodionov, sent a secret message warning Pakistan that escalating tensions would lead it down a “suicidal course.”

The United States, on the other hand, supported Pakistan politically, economically, and militarily. President Richard Nixon and Secretary of State Henry Kissinger refrained from using harsh rhetoric or intervening directly in the civil war, believing that the Soviet Union was aligned with India. The U.S. saw Pakistan as a key ally in containing Soviet influence in South Asia, especially given Pakistan’s strategic relationship with China, with whom Nixon was seeking closer ties.

Nixon also feared that an Indian victory could lead to Soviet dominance in the region and undermine the global position of the U.S. He encouraged Iran to send military supplies to Pakistan and ignored reports of atrocities by the Pakistani military, including the Blood Telegram, which criticized the violence in East Pakistan. This decision was met with widespread criticism from both the U.S. Congress and international media.

U.S. Ambassador to the UN, George H.W. Bush, proposed a ceasefire resolution at the UN Security Council, which was vetoed by the Soviet Union. As the conflict escalated, Nixon deployed Task Force 74, led by the aircraft carrier USS Enterprise, to the Bay of Bengal. In response, the Soviet Navy sent cruisers and destroyers to the region to monitor the U.S. presence. As it became clear that India was poised to defeat Pakistan, Nixon contacted Soviet General Secretary Leonid Brezhnev, urging him to restrain India, but to no avail.

After the war, the U.S. adjusted to the new regional power dynamics and recognized India as the dominant force in South Asia, focusing on strengthening bilateral relations in the subsequent years. Meanwhile, the Soviet Union continued to support Pakistan economically, particularly in technical and industrial projects.

A 2019 study suggests that Nixon and Kissinger overestimated the likelihood of a Pakistani victory and misjudged the importance of the crisis in their broader policy objectives. The study argues that their decisions ultimately undermined their stated goals.

China
Throughout the conflict, China strongly criticized India’s involvement in the East Pakistan crisis, accusing India of imperialistic motives in South Asia. Prior to the war, China had urged Pakistan to pursue peaceful political solutions with East Pakistan, fearing Indian support for the Bengali rebels. China also opposed the ruthless measures employed by Pakistan’s Governor of East Pakistan, Lieutenant-General Tikka Khan, against the opposition.

When the war broke out, China condemned India’s direct intervention and criticized Pakistani President Yahya Khan’s military approach, along with the Awami League’s alleged ties to India. China grew increasingly concerned as India’s potential invasion of Pakistan seemed imminent. U.S. President Nixon encouraged China to mobilize its forces along the Indian border, but China did not act, as India’s Northern Command was already engaged along the Line of Control with Pakistan’s X Corps.

China did not support the breakup of Pakistan and vetoed Bangladesh’s membership in the United Nations in 1972, citing unresolved issues related to the repatriation of Pakistani POWs and civilians. China was one of the last countries to recognize Bangladesh’s independence, doing so in August 1975. Its relationship with Bangladesh has been largely shaped by its ties with Pakistan.

Ceylon (Sri Lanka)
Sri Lanka, then known as Ceylon, viewed the partition of Pakistan with concern, as it feared that India’s growing power could be used against them in the future. During the war, Pakistani aircraft were refueled at Bandaranaike Airport in Sri Lanka, allowing them to bypass Indian airspace on their way to East Pakistan. This action did not result in strained relations between Sri Lanka and India.

Arab World
Many Arab countries had close ties with both the United States and Pakistan, making it easier for Kissinger to encourage their participation. He sent letters to King Hussein of Jordan and King Faisal of Saudi Arabia, with the U.S. giving permission for Jordan to send ten F-104 fighter jets to Pakistan. Saudi Arabia also provided F-86 aircraft to help obscure the extent of Pakistani losses. Additionally, Libya reportedly sent F-5 fighters to Pakistan, possibly for training purposes as part of a larger plan to prepare Pakistani pilots for a potential influx of F-5s from Saudi Arabia.

Israel
Although Israel did not have formal diplomatic relations with India at the time, it provided India with military assistance, including armaments, ammunition, intelligence, and training. This support was seen as a minor success in India’s efforts to garner international backing. In July 1971, Israeli Prime Minister Golda Meir facilitated the supply of mortars, ammunition, and instructors to India and the Mukti Bahini. Meir also reportedly sought to establish diplomatic ties with India in exchange for this assistance, which was eventually realized in 1992 under P.V. Narasimha Rao’s government.

Shimla Agreement

On 2 July 1972, the Indo-Pakistani summit took place in Simla, Himachal Pradesh, India, where the Simla Agreement was signed between President Zulfikar Ali Bhutto and Prime Minister Indira Gandhi. The agreement assured Bangladesh of Pakistan’s recognition of its sovereignty in exchange for the return of Pakistani prisoners of war. Over the following five months, India released more than 90,000 POWs, with Lieutenant-General A.A.K. Niazi being the last to be handed over to Pakistan.

The treaty also saw the return of more than 13,000 km² of territory that the Indian Army had captured during the war, though India retained some strategic areas, including Turtuk, Dhothang, Tyakshi (formerly Tiaqsi), and Chalunka in Chorbat Valley, which totaled over 883 km². Indian hardliners, however, felt the treaty was too lenient toward President Bhutto, who had pleaded for leniency, fearing that any harsh terms would destabilize Pakistan further and lead to accusations of losing Kashmir in addition to East Pakistan. As a result, Prime Minister Gandhi faced criticism in India for trusting Bhutto’s “sweet talk and false vows,” while others believed the agreement was successful, avoiding a “Versailles Syndrome” and ensuring stability.

In 1973, India and Pakistan reached another agreement, the Delhi Agreement, which, along with Bangladesh, facilitated the return of war prisoners, non-Bengali civilians, and Pakistani-loyal Bengali bureaucrats to Pakistan. This marked the largest mass population transfer since the 1947 Partition of India.

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