AGARTALA, EAST PAKISTAN.-War is hell, everyone says, but it is usually hell for both sides.

Yet, in the three-week-old war between the Pakistani Army and the outgunned resistance fighters of East Pakistan, there has been only one hell so far-that of the tens of thousands of East Pakistani civilians who have been massacred by the army in its drive to terrorize, Intimidate and crush the Bengali independence movement.

Having gained control of most of the major cities and towns, the army troops-all are West Pakistanis, many of whom harbor deep racial hatred for the Bengali population of East Pakistan-are now making forays into the countryside. They hope to extend their control before the monsoon rains ,become heavy in a few weeks and make movement for a regular army difficult.

"They flounder and die in knee-deep water," said a Bengali officer. "We will use country boats. We will make misery for them."

The prospect is for a long, sullen war. Most diplomats and foreign observers believe ,that the Bengalis, by hanging on, will eventually make life untenable for the West Pakistanis, who are more than 1,000 miles from their home and their supply bases.

But these observers also agree that, unless foreign powers put an economic squeeze on the Pakistani Government, it could be years before the 75 million Bengalis finally win their freedom and end West Pakistan's exploitation of their province-the exploitation that gave birth to the independence movement.

There are usually two sides to every story, every argument, every conflict. But it is difficult, after witnessing what is taking place in East Pakistan, to imagine some justification for the army's action. This is because the army, from all the available evidence has set out to kill the leaders and potential leaders of East Pakistan and to destroy the economic base of the region.

"They want to drag us so far down that we will be reduced to eating grass," said one Bengali soldier. "They want to make sure that no head will ever be raised against them again."

The West Pakistani troops are killing Bengali students, intellectuals, professors, army officers, engineers, doctors and others of any leadership potential.

Using tanks, jet fighter-bombers, heavy artillery and gunboats, all mostly supplied by the United States, the Soviet Union and communist China, the Pakistani Army is also destroying food-storage houses, tea factories jute mills and natural gas fields-the economic infrastructure of East Pakistan.

SHOELESS SOLDIERS

The largest weapon the resistance army has is the three-inch mortar, although it has captured a few heavy guns. Some of the Bengali soldiers have no shoes. The Bengalis-their core of trained troops number only 12,000 to 15,000, all of whom fled the ranks of the Pakistan Army when the attack began-cannot afford frontal clashes with the estimated 60,000 to 80,000 West Pakistani troops in East Pakistan. So the Bengali strategy is now based on hit-and-run guerrilla tactics.

The independence movement has formed a provisional government, but for the moment this is largely a move to keep Bengali morale from flagging and to try to coordinate the war effort.

As the war continues, the economies of both East and West Pakistan are suffering badly. Frightened Bengali peasants are not risking going into their open fields to plant rice this year, East Pakistan's jute is not being exported and West Pakistan's big textile industry is unable to sell the Bengalis its over-priced sleazy cottons, for which there is no other market. The Bengali nationalists may be able to hold out by living off the familiar land. For West Pakistan, the key may be foreign aid.

One question mark is whether Communist China will provide enough aid to allow the Pakistanis to pursue their offensive indefinitely. In a note to the Pakistani Government last week, Premier Chou En-lai denounced the United States, the Soviet Union and India for "carrying out gross interference in the internal affairs of Pakistan" and promised China's support "should the Indian expansionists dare to launch aggression against Pakistan.

Another similar question is whether the Western aid- giving community, particularly the United States, which is now giving Pakistan about $175-million a year, will withhold all further assistance until President Yahya Khan stops the bloodshed.

The State Department's desire is to try to press for a political settlement, remote as that possibility is This strategy runs the heavy risk not only of failing in West Pakistan, where the Americans want to keep a foothold to keep Chinese influence from becoming predominant, but also of losing all the East Pakistani goodwill it had in the strongly pro-Western independence movements.

The Pakistan Government, often through its official radio, is accusing its old enemy India of virtually everything in this war: of sending arms and soldiers to the independence army, of harassing Pakistani ships, of setting up a clandestine radio station, of inspiring the Indian press to print exaggerated accounts of massacres and atrocities. These charges, all of which India has repeatedly denied, have received wide play in the world press, mainly because there is no Bangla Desh radio to counterbalance them.

India is probably providing assistance to the independence movement, but there has been no evidence yet of any arms, ammunition or men.

Radio Pakistan and the controlled West Pakistan press, in addition to using India for a whipping boy, also continues to issue daily reports describing conditions in East Pakistan as "returning to normal." It characterizes the popularly supported independence movement as "a handful of miscreants" and says that the East Pakistan economy is on the mend, with jute being exported again. All are bald fabrications.