Dacca: Two flags went up in Pakistan last Tuesday to commemorate the same moment in the country's history. In the western wing, the national flag fluttered as President Yahya Khan spoke in Dacca of his vision of the glory and integrity of Pakistan, and looked back to the 1940 Lahore Resolution in which the All-India Moslem League stated its determination to create a homeland for the subcontinental Moslems.

Simultaneously the people of the East observed a "resistance day", saluted their new "Bangla desh" banner and reminded Yahya through the mass media that the Lahore resolution had envisaged "independent states in which the constituent units shall be autonomous and sovereign".

Last week East Pakistan's Sheikh Mujibur Rahman looked increasingly nearer that goal - after almost a month of civil disobedience in revolt against what Mujib has called the suppression of the majority. He was still in full control of the region, though its economy is suffering severe blows. The Sheikh is relatively untroubled by this, so long as his primary aim is achieved: to impress the West Pakistanis in general and the army they dominate in particular with his undoubted popularity and strength.

Last week Yahya seemed chiefly concerned to salvage what unity he could between the two wings and secure the country from a total breakup. His offers to Mujib were interim solutions, to enable a smooth transfer of power from the military to the elected politicians.

But though the two leaders were said to have reached a general understanding even on the future role of the armed forces, it is still open to question whether Mujib will be willing to take over responsibility for the whole of Pakistan while his followers in the streets of Dacca continue to demand "shadin Bangla" (independent Bengal). The president again postponed the national assembly scheduled to meet on March 25 and called all West Pakistan's leaders to the eastern wing.

Zulfikar Ali Bhutto, PPP (Pakistan People's Party) leader and Mujib's chief rival, reluctantly abandoned (by implication) his proposal for a prime minister for each wing and went to Dacca, along with Wali Khan (National Awami League leader). Bhutto was received as Bangla's enemy number one and had to be taken under military protection but started "satisfactory and fruitful" discussions with Mujib.

The big question remains: how to combine the East's demand for semisovereign status with an agreement acceptable to the four western provinces - which are themselves subject to similar centrifugal pressures. The Pathans and the Baluchis have already protested against the re-establishment of "one unit" in the West.

Bhutto backs the idea, which obviously would make it easier to maintain a federal balance between the two halves; but the smaller provinces are fearful of being again subjected to Punjabi domination. The problem of Pakistan's unity is no longer simply "Bangla desh".