Calcutta: There is reason to believe a classic guerrilla organisation is taking shape in East Pakistan. Militant peasants, under the popular leadership of Maulana Bashani, have long been geared for just such an organisation, especially in the northern districts. Now, according to East Pakistani sources, two significant factors have emerged.

First, the substantial East Pakistani population living abroad seems to have started organising meaningful support. The initiative has been taken in London and the plan reportedly is to raise funds with which to supply arms to the freedom fighters at home.

Second, most of the 1,340-mile border with India is unsealable and the Bengalis of India have fully identified themselves with the East Pakistani cause. The Indian government may be profoundly worried about the future implications of a Bangla Desh but, for the present, it will be unable to prevent West Bengal and even Assam and Tripura states from becoming the "reliable rear area" of liberation forces in East Pakistan. Supply of food as well as of arms will be organised across these borders.

It is stressed too that Sheikh Mujibur Rahman's personal leadership is not required for an indefinite liberation struggle. There have been groups in the Awami League and outside which have thought of a confrontation with the army, and even discussed details such as which weapons would be best in such an eventuality. Tiers of organised and competent leadership are said to be ready to take over.

The suddenness and finality with which leaders in West Pakistan pushed the east wing beyond the point of no return has been the main topic of discussion since the crisis started. Circumstantial evidence suggested President Yahya Khan was merely play-acting when. he held prolonged discussions with Sheikh Mujib in Dacca until March 25, that in fact he was waiting for troop ships to arrive from West Pakistan.

This conspiracy theory has found wide acceptance among close observers.

However, information from some informed sources points to the possibility that the principal conspirator was not Yahya, nor indeed People's Party leader Zulfikar Ali Bhutto: it was a small coterie of hawks in the army. Even before the December election a group of top army officers had disagreed strongly with Yahya Khan's blueprint for democracy and argued for continued military rule. Their manoeuvres had given rise to rumours, heard briefly in the wake of the East Pakistan cyclone in November, that Yahya had become something of a figurehead.

After the elections they reportedly forced the pace. The reason for postponing the National Assembly session from March 3 was inferred publicly to be Bhutto's threat to boycott the session. In fact, say sources with access to the Awami League leadership, the postponement decision was forced upon Yahya before Bhutto announced his boycott move. The army is said to have taken advantage of the failure of the Bhutto-Mujib talks in Dacca and insisted that the only way to avoid political chaos was to call a halt to the assembly experiment. Having heard of the army hawks' move, Mujib seems to have sent an emissary to Islamabad to warn the president that a postponement of the assembly session would worsen the East Pakistan situation. The emissary, it appears, never succeeded in getting an audience with the president.

According to a diplomatic source, there was one round which Yahya won in his running battle with the army. This was following the mass rally in Dacca on March 7. Leaders in the west wing were sure this would be the occasion for what they called UDI (Rhodesia-style unilateral declaration of independence).

The assumption was based on the fever pitch which Bengali nationalist feelings had reached following the assembly postponement. A few hours before the rally was to begin, some 10,000 emotion-charged people went to the Sheikh's house, invited him to get into a big limousine, flying a black flag, drive to the Paltan grounds and there declare the birth of independent Bangla Desh. The Sheikh spoke affably to them for a while, then got into a small car. At the rally ground, a wildly emotional multitude seemed in no mood for anything except independence then and there The Sheikh shrewdly asked the Maulvis (religious leaders) to start reciting immediately from the Koran. This is a common practice in Pakistan and the rule is that while recitations are going on, people should remain absolutely calm, silent and orderly. The long Koran recitation cooled tempers. At the end of it, before the people had time to raise slogans and work up emotions afresh, the Sheikh grabbed the microphone and started his speech. And during the speech, he stopped short of UDI.

The deftness with which the Sheikh managed the explosive situation is reported to have impressed Yahya Khan and, more importantly, given him an opportunity to impress upon his army colleagues that the Sheikh was a responsible leader with whom it was possible to do business. It was on this note that he took off for Dacca.

During the Dacca conference, the army's pressure on Yahya continued. Sheikh Mujib himself was under heavy pressure from his own followers to strike out for independence. When the talks became prolonged, with Mujib calling for immediate transfer of power, the army group again took the reins of power from Yahya. According to the diplomatic sources, it was this group which ordered the precipitate actions: vetoing of the "compromise formula" Yahya Khan reportedly agreed to in Dacca; imposition of strict martial law in East Pakistani cities; the use of tanks and bombers.

Sources say the army group had been making its own preparations for the showdown. Simultaneously with the National Assembly postponement, key martial law administrators were changed. The tough Tikka Khan was posted to Dacca. At least six shiploads of troops were sent to the east well before the Yahya-Mujib talks had a chance to start. When Yahya was in Dacca, or just before, measures were taken to control the remittance of foreign currency to East Pakistan and to prevent East Pakistanis using demand drafts abroad.

It is remembered that once before the army had put Sheikh Mujib on an execution list. In 1958 General Azam Khan, then a member of the Ayub Khan cabinet, had suggested that about eight political leaders in the east wing be quietly shot as their continued existence would mean only trouble in the long run. The Sheikh and Maulana Bashani headed that list. Ayub did not want to go to that extreme at that time. Later he spilled the beans about the liquidation list when Azam Khan, in a political turnabout, opposed Ayub's candidacy in the subsequent election and joined Maulana Bashani to support Fatima Jinnah in vain.