Even as the role of the Indian military in giving birth to the new nation is celebrated, the role of its intelligence services remains largely unknown.

Forty-five minutes before 12.00 pm on December 14, 1971, Indian Air Force pilots at Hashimpara and Gauhati received instructions to attack an unusual target: a sprawling colonial-era building in the middle of Dacca that had no apparent military value whatsoever.

There were nothing but tourist maps available to guide the pilots to their target — but the results were still lethal. The first wave of combat jets, four MiG21 jets armed with rockets, destroyed a conference hall; two more MiGs and two Hunter bombers levelled a third of the main building.

Inside the building — the Government House — East Pakistan's Cabinet had begun an emergency meeting to discuss the political measures to avoid the looming surrender of their army at Dacca 55 minutes before the bombs hit. It turned out to be the last-ever meeting of the Cabinet. A.M. Malik, head of the East Pakistan government, survived the bombing along with his Cabinet — but resigned on the spot, among the burning ruins; the nervous system, as it were, of decision-making had been destroyed.

For years now, military historians have wondered precisely how the Government House was targeted with such precision; rumours that a spy was present have proliferated. From the still-classified official history of the 1971 war, we now know the answer. Indian cryptanalysts, or code-breakers, had succeeded in breaking Pakistan's military cipher — giving the country's intelligence services real-time information on the enemy's strategic decision-making.

India's Army, Navy and Air Force were lauded, during the celebrations of the 40th anniversary of Bangladesh's independence, for their role in ending a genocide and giving birth to a new nation. The enormous strategic contribution of India's intelligence services, however, has gone largely unacknowledged.

Seven months before the December 3 Pakistan Air Force raid that marked the beginning of the war, India's Chief of Army Staff issued a secret order to the General Officer Commanding, Eastern Command, initiating the campaign that would end with the dismemberment of Pakistan.

Operation Instruction 52 formally committed the Indian forces to “assist the Provisional Government of Bangladesh to rally the people of East Bengal in support of the liberation movement,” and “to raise, equip and train East Bengal cadres for guerrilla operations for employment in their own native land.”

The Eastern Command was to ensure that the guerrilla forces were to work towards “tying down the Pak [Pakistan] Military forces in protective tasks in East Bengal,” “sap and corrode the morale of the Pak forces in the Eastern theatre and simultaneously to impair their logistic capability for undertaking any offensive against Assam and West Bengal,” and, finally, be used along with the regular Indian troops “in the event of Pakistan initiating hostilities against us.”

Secret army

The task of realising these orders fell on Sujan Singh Uban. Brigadier — later Major-General — Uban was an artillery officer who had been handpicked to lead the Special Frontier Force, a secret army set up decades earlier with the assistance of the United States' Central Intelligence Agency to harry the Chinese forces in Tibet. The SFF, which until recently served as a kind of armed wing of India's external covert service, the Research and Analysis Wing, never did fight in China. In Bangladesh, the contributions of its men and officers would be invaluable.

Brigadier Uban — whose enthusiasm for irregular warfare was rivalled, contemporaries recall, only by his eccentric spiritualism — later said he had received a year's advance warning of the task that lay ahead from the Bengali mystic, Baba Onkarnath.

Less-than-holy war

The war he waged, though, was less-than-holy. In July 1971, India's war history records, the first Bangladesh irregulars were infiltrated across the border at Madaripur. This first group of 110 guerrillas destroyed tea gardens, riverboats and railway tracks — acts that tied down troops, undermined East Pakistan's economy and, the history says, destroyed “communications between Dhaka, Comilla and Chittagong.”

Much of the guerrilla war, however, was waged by the volunteers of the Gano Bahini, a volunteer force. The Indian forces initially set up six camps for recruiting and training volunteers, which were soon swamped. At one camp, some 3,000 young men had to wait up to two months for induction, although the “hygienic condition was pitiable and food and water supply almost non-existent.”

By September 1971, though, Indian training operations had expanded dramatically in scale, processing a staggering 20,000 guerrillas each month. Eight Indian soldiers were committed to every 100 trainees at 10 camps. On the eve of the war, at the end of November 1971, over 83,000 Gano Bahini fighters had been trained, 51,000 of whom were operating in East Pakistan — a guerrilla operation perhaps unrivalled in scale until that time. In the Chittagong Hill Tracts, Brigadier Uban sent in Indian soldiers or, to be more exact, CIA-trained, Indian-funded Tibetans using hastily-imported Bulgarian assault rifles and U.S.-manufactured carbines to obscure their links to India. Fighting under the direct command of RAW's legendary spymaster Rameshwar Kao, Brig. Uban's forces engaged in a series of low-grade border skirmishes.

Founded in 1962, the SFF had originally been called Establishment 22 — and still has a road named after it in New Delhi, next to the headquarters of the Defence Ministry. The organisation received extensive special operations training from the U.S., as part of a package of military assistance. In September 1967, the control of these assets was formally handed over to RAW — and used in Bangladesh to lethal effect.

From December 3, 1971, Brig. Uban's force began an extraordinary campaign of sabotage and harassment. At the cost of just 56 dead and 190 wounded, the SFF succeeded in destroying several key bridges, and in ensuring that Pakistan's 97 Independent Brigade and crack 2 Commando Battalion remained bogged down in the Chittagong Hill Tracts. Some 580 members of Brig. Uban's covert force were awarded cash, medals and prizes by the Government of India.

November 1971 saw the Indian-backed low-intensity war in East Pakistan escalate to levels Pakistan found intolerable — pushing it to act. On December 3, Pakistan attempted to relieve the pressure on its eastern wing by carrying out strikes on major Indian airbases. India retaliated with an offensive of extraordinary speed that has been described as a “blitzkrieg without tanks.”

Rejecting an offer for conditional surrender in the East, the Indian forces entered Dacca on December 15. Prime Minister Indira Gandhi promptly ordered a ceasefire on the western front as well: “if I don't do so today,” she said of the decision to end the war, “I shall not be able to do so tomorrow.”

How important was the covert war to this victory, and what cost did it come at?

India's new communications intelligence technologies were clearly critical; three decades on, the government would be advised to make fuller accounts public, and publicly honour the anonymous cryptanalysts who achieved so much.

The 1971 war history records that their efforts meant “several important communications and projections of the Pak[istani] high command were intercepted, decoded and suitable action [was] taken.” Indian communications interception, the history states, even prevented a last-minute effort to evacuate the Pakistani troops from Dacca, using five disguised merchant ships.

The role of irregular forces, though, needs a more nuanced assessment. There is no doubt that they served to tie down Pakistani troops, and derail their logistical backbone. They were also, however, responsible for large-scale human rights abuses targeting Pakistani sympathisers and the ethnic Bihari population. There is no moral equivalence between these crimes and those of the Pakistani armed forces in 1971 — but the fact also is that the irregular forces bequeathed to Bangladesh a militarised political culture that would have deadly consequences of its own.

India's secret war in Bangladesh would have served little purpose without a conventional, disciplined military force to secure a decisive victory — a lesson of the utility and limitations of sub-conventional warfare that ought to be closely studied today by the several states that rely on these tactics.