THE REBELLION against the government of Bangladesh collapsed quickly, leaving the constitutional authorities shaken but still in charge. The country has, nonetheless, suffered a loss of sort that desperately undeveloped countries like Bangladesh are least fit to sustain. The president, a remarkable retired general name Ziau Rahman, was killed in the aborted coup.

Presient Zia was treated on all sides as his country's chief asset. He had come to power as the result of intrigue but he needed martial law, restored fundatmental rights and held respectable elections in 1978 in which he won 77 percent of the vote. Inevitably he was compared with President Zia of Pakistan, the country Bangladesh broke from in 1971, who spent the same period consolidating his personal rule.

President Zia of Bangladesh was best known for his passionate and, in the Third World, rare devotion to village-level economic development. Not one simple to issue directives from the capital, he spent 20 days a month visiting peasants, exhorting them to learn to read, to grow more food and to limit family size. He was getting results, too, his World Bank admirers believed. Bangladesh, tagged cruelly but accurately by Henry Kissinger as an "international basket case," is among the poorest, fastest growing and most crowded countries in the world and requires large and continuing amounts of aid just to make marginal gains in its extremely low standard of living. Still, it has approached a locally defined condition of food self-sufficiency in good years, shown a regionally respectable rate of economic growth and measurably improved its level of economic management.

Some part of this progress appears to bear on President Zia's murder. The purposes of the army rebels are not clear. The crowds that mourned him proved anew that he was genuinely popular, but he had political rivals, and statements of the rebels suggest a connection to some of them. In any developing society, there is always enough corruption and inefficiency to spark political protest. The possibility is very real, however, that powerful social groups saw his policies of democracy and development as a threat to their position and privilege. Unfortunately, the limits to growth in poor countries are not strictly economic.

The immediate test will be wether the constitutional procedure for replacing him can be observed. Then Bandladesh faces the harder task of somehow finding a substitute for the leadership of President Zia and regaining the momentum that was his most precious contribution to his country.