IN THE HOURS that have passed since Saturday night, when the bombs exploded in the Sari club in Bali, one phrase has been heard more than any other. The taxi driver used it as I came in from the airport on Sunday evening. The clerk at the hotel said the same thing, and even the young man who led me to my room. It was there that evening in the television news, and yesterday it was being passed round among the police officers, doctors, medical orderlies, volunteers, consular workers and counsellors who have mobilised to deal with the tragedy. Perhaps all disasters generate such phrases, which are seized upon by people for whom nothing seems to make sense any more. The phrase is a simple one: “Indonesia has never seen anything like it.”

On the face of it, this is nothing more than a statement of the obvious. For nothing quite like it has happened anywhere in Indonesia — and certainly not on Bali, the small, numinous island at the centre of the archipelago. At least 181 people died on Saturday night, most of them during a few seconds of intense heat and blast when a vast bomb, presumably planted in a truck, exploded next to one of Bali’s busiest nightclubs.

No Indonesian policeman has ever had to deal with 181 murders in one night. No doctor has had 181 sets of remains, most of them foreigners, to store, identify, and issue death certificates for. In its focus and intensity, in its calculated meanness — above all, in its international impact — this was an unprecedented atrocity, the impact of which will last for a generation. And yet in plenty of ways it was predictable, the logical culmination of decades of neglect and suffering. Car bombs and high explosives may be new to Indonesia, but at its root this is a story about repression, poverty, and religious and ethnic strife. And few countries know more about these afflictions than Indonesia.

In the past five years, Indonesians have witnessed conflict of a variety and savagery which few nations experience in a generation. On the island of Borneo there have been three separate headhunting wars in which local tribespeople have hunted down and cannibalised immigrant settlers.

In the province formerly known as the Spice Islands, Christians and Muslims have transformed the city of Ambon into a tropical Beirut. In East Java, and even in Bali, villagers have been murdered and cut to pieces, not for their religion or race but for the alleged practice of black magic.

In various corners of Indonesia you can find pirates, gangsters and smugglers, all with their own rackets to defend and their own reasons to kill. In Aceh and Papua, guerrilla armies wage ongoing struggles for independence. The people of East Timor won their independence in a UN referendum, only to see their new country devastated by the departing Indonesian Army. More may have died in Cambodia or Rwanda or Yugoslavia, but not for such a dazzling array of intricate and individual reasons. Put in such a perspective, the murderous terrorism in Bali seems less like an aberration, and more like just another item on an agonisingly long list.

Yet beyond all this is the reason that brings people back to Bali and, in lesser numbers, to the 13,000 other islands — the charm, warmth and unselfish good nature of the people. To say that Indonesians are gentle and friendly is the truest and most banal of observations, like saying that their weather is warm and their seas blue; over centuries of immigration and trade they have demonstrated their tolerance of different races, religions and languages.

All cultures are paradoxical, but it is hard to think of a country which contains such extremes of gentleness and violence, of gracious hospitality alongside bestial cruelty.

Perhaps it is misleading to speak of Indonesia as a country at all. In many respects it has more in common with an ancient empire ruled from Java — the beautiful island, about the size of England, which contains about half of its 212 million people.

As a nation it was born in 1945 after the Japanese had expelled the Dutch from what had been the Dutch East Indies. Even today, many parts of the country have nothing more in common with one another than the fact that hundreds of years ago they were colonised by the Netherlands. The distance from one end of the country to the other is as far as from Britain to Iraq.

Within that arc of islands are people who range from Jakarta yuppies to Papuan tribespeople who are no more than a generation from the Stone Age. Two centuries of exploitative Dutch rule were followed by 20 tumultuous years of relative freedom. Then, in a creeping and protracted coup, the founding president, Sukarno, was replaced by a general named Suharto who remained in power for 32 years.

Under Suharto the economy grew, life expectancy and literacy increased and most Indonesians became better off. But the rewards of development were disproportionately concentrated in the hands of a few friends and relatives of the dictator. Beneath a veneer of pseudo-democracy, political opposition was outlawed and those who insisted on standing up to Suharto — such as the people of East Timor, invaded by Indonesia in 1976 — were ruthlessly and bloodily suppressed.

The powerful countries of the West colluded in all of this; in return Suharto gave them access to his growing markets and passive but uncompromising support in the Cold War. Suharto was the opposite of a communist dictator, but when he was was driven from power in 1998 by student demonstrations and urban riots, Indonesia began to look more and more like a tropical Soviet Union or Yugoslavia.