To the Editor: The exclusion of the foreign press and observers from East Pakistan has meant the loss of vital information on the course of events there and will deprive us of the dramatic facts that rouse individuals and governments to action. But there is enough conducive evidence from past and recent history to predict the result of the present conflict on the food position of the province.

The food grains that sustain a large part of the Bengal' population come from abroad. Their distribution depends on the effective functioning of the port of Chittagong and on internal transportation and administrative services.

East Pakistan, with a population of more than seventy million, expected 2.6 million tons of imported food grains this year. That is about one-sixth of the total food requirements for the province, enough to feed twelve million people. However, a far greater number is actually affected by an interruption in the steady flow of food. For the 60 per cent of the population living barely at subsistence level, these supplies maintain the balance between life and death. Bengal has always been extremely susceptible to famine. The last such disaster occurred in 1943 when food expected from Burma did not arrive because of the Japanese occupation of that country. At that time military demands on the Indian transportation system prevented the timely distribution of the food that was available. The food deficit that year was 6 per cent; this year it is 16 per cent. Deaths in 1943 numbered 1.6 million, and the famine left social problems from which Bengal has yet to recover fully.

A crisis was imminent in 1966 when the Indo- Pakistani war stopped imports. it was avoided when the great powers used their influence to bring that conflict to a speedy close. Recovery was aided by normal internal supply activities, which had been unaffected by the war.

Today, in contrast, not only has the import of food been cut off, but the internal administrative and transport services have ceased to function normally. In addition, military action at planting time will reduce the coming harvest.

The regular import of food has been interrupted since February. Even if the conflict were to end today, the months required to return the system to normal would probably exceed the time during which the food reserves could sustain the population. The factors that determine mass famine are irreversible after a certain point.

When the first Caries and photographs of starving families are published, it will be too late to protect thousands of others. International action, immediate and strong, is perhaps the only defense the people of East Bengal now have. DANIEL C. DUNHAM. NEW YORK, April 20, 1971.