It happened in Cairo in 1977. Then in Casablanca in 1981. And now in Tunis. ''It'' is the explosion of popular fury that can follow a third-world government's decision to raise the price of bread. In Tunisia, relative calm has returned after a week of rioting that may have killed more than 50 people, injured hundreds, and led to some 1,000 arrests. To restore order, the government was forced to do an about-face.
Over the weekend Tunisian President Habib Bourguiba rescinded the 80- to 110 -percent price increases for bread and cereals that sparked the riots. He also dismissed Interior Minister Driss Guiga, who apparently has been chosen to take the blame.
Over the long term, the rioting poses many troubling questions for the leadership of the country that is supposed to be the most stable in North Africa , and which has enjoyed a relative degree of economic progress. The government's clumsy handling of the price increases has damaged its credibility and tarnished the image of Prime Minister Mohamed Mzali, architect of the price rises and until now the likely successor to Mr. Bourguiba.
The move also revealed how many Tunisians live on a thin margin of survival. For some Tunisian households, bread and semolina constitute 80 percent of the food budget.
Political observers in Tunis and Paris say that the riots signified much more than a protest against a rise in the price of bread. The numbers of young people in the street, and the religious slogans they chanted point to deeper causes. As in a number of other Arab countries, many young educated Tunisians feel disfranchised. They have grown up with high expectations fostered by a Western-minded President and fueled by the tantalizing proximity of Western consumer goods.
Yet recession, unemployment, and underdevelopment have deprived many young people of the goods they would like to enjoy. It was no surprise that the young rioters attacked symbols of Western consumer society: travel agencies, Western boutiques, and supermarkets.
As many Arab countries are having to do, the Bourguiba government must decide how to handle the delicate issue of rising Islamic fundamentalism and growing anti-Westernism in Tunisia.
In 1981, the government launched a crackdown against Islamic fundamentalists in Tunisia, imprisoning many of the movement's leaders. But many of the economic safety valves that weakened the fundamentalist appeal are being shut off: Emigration to France for work is no longer feasible; the Gulf countries can no longer soak up excess labor.
Twenty to 25 percent of the work force is unemployed or only seasonally employed. With 60 percent of the population under age 20, Tunisia has a demographic time bomb on its hands.
Bourguiba seems to have expressed renewed confidence in Mr. Mzali. He gave the prime minister temporary charge of the Interior Ministry, and asked him to present a new budget in three months that will protect the poor against future price rises.
Still, last week's events may intensify the infighting in the Tunisian government for succession to the presidency of 83-year-old Bourguiba, who has ruled the country since it gained independence 27 years ago.
Bourguiba will have to decide whether he should continue the process of cautious liberalization begun last November to increase possibilities for political expression, or whether he should opt for a stricter policy.