YVES VOLEL, a candidate for president of Haiti, was not only assassinated. He was assassinated in front of the police headquarters in Port-au-Prince by men who, witnesses said, seemed to be plainclothes policemen and who immediately confiscated the cameras and film of the news photographers and a television crew who were there.

He is the second political figure to die in this campaign. Two months ago the leader of one of the smaller parties was hacked to death in a rural village. But the violence in July and early August then diminished. This latest crime is a very bad sign.

There are two conflicting views of these events. One holds that the widespread bloodshed in Haiti is the reflection of a state of chaos in a country in which police and soldiers are poorly trained and badly frightened. Because of their association with the Duvalier family's long dictatorship, they are on the defensive; they react ineptly and excessively to any kind of challenge. The present provisional government under Gen. Henri Namphy is weak and exercises little control over its own forces.

The alternative view is that, while Jean-Claude Duvalier has fled to exile, most of the Duvalierists -- people who supported him, and were supported by his regime -- remain in Haiti. They are now at work, many Haitians charge, fomenting bloodshed to create a climate of intimidation in which the presidential election to be held late next month will, if it takes place at all, be meaningless.

Perhaps those charges are overdrawn. But it is true that a country does not become as deeply impoverished as Haiti by any natural process, or by the mere absence of good government. Its destitution is the product of a tradition in which a few people have become, by Haitian standards, rich through a system of monopolies and privileges that have kept the rest of the country bitterly poor -- and that system is now threatened by the prospect of democracy. Which explanation, chaos or conspiracy, is correct? Perhaps, to one degree or another, both.

Fortunately, there are courageous and determined Haitians to defend the cause of democracy and the election process that is now coming to a climax. One useful thing that Haiti's friends and neighbors can do -- and are doing -- is to send observers to watch the final stages of this campaign and the voting. Any election benefits from the presence of a large and vigilant audience