RAMEH, Israel (AP) _ When the 21-year-old soldier decided his older sister visiting from the United States was a stain on the family honor, he killed her with 20 shots from his assault rifle.

Police said Hussam Bassam declared he was driven to the murder by the 38- year-old's dyed blond hair, miniskirts and general attitude of challenging Druse traditions.

Her father would not accept condolences, explaining that the death was akin to the amputation of an injured finger.

The tragedy in this pastoral Arab village focused attention throughout Israel and the occupied territories on honor killings, a centuries-old form of murder that had traditionally been swept into the family closet.

The extent of the problem is difficult to gauge. But the public response this time indicated things may be changing in Arab society.

Family honor must be redefined and a system set up ''whereby such killings will be totally unacceptable and abhorred rather than accepted,'' said Hanan Ashrawi, a former Palestinian spokeswoman now focusing on human rights.

In traditional Arab societies, family honor rises or falls according to the women's personal and social behavior as defined by rigid moral codes.

The Druse, a small Islamic sect, are considered especially rigid and secretive about their social traditions. They are the one of the few Arab groups that serve in the Israeli army.

Family honor killings are tacitly accepted, and many are disguised as suicides or accidents. Few statistics are available; only about five deaths are recorded yearly by the Social and Welfare Ministry among Israeli Arabs.

In the occupied territories no data is available. However, 107 women were recorded killed as suspected informers and violators of the moral code during the six-year uprising against Israeli rule.

In Israeli courts, honor killings are considered murder and perpetrators face a life sentence. In the West Bank and Gaza Strip such crimes have a maximum sentence of two years; those convicted are usually released early.

Neighbors in Rameh, 75 miles north of Jerusalem, provided an account of Ikhlas Bassam's death, but it was not always possible to separate fact from rumor.

Ikhlas was back for a summer visit to her native village from the New York City area, where she had gone to live with a brother about 15 years ago, and where she used the name Ruth Simons. The family had visited her there.

She was outspoken about the need for modern institutions in the Galilee, the northern Arab heartland of Israel. She went on television in July to discuss her attempts to organize a Druse orphanage and an old people's home.

But rumors flowing through Rameh about her included an affair with an uncle in the village, an affair with a black man in the United States and a marriage out of the faith. She was also accused of running a whorehouse.

All villagers know for sure is that Hussam shot Ikhlas dead after an argument when she came home from the July 8 interview.

Some don't think it was an honor killing at all but an argument over money that go out of hand and was disguised to be more acceptable locally.

''I am very frustrated and in despair,'' said Rula Deeb, a member of the Arab-Israeli feminist group Woman to Woman and a Rameh resident.

''This is a very inflexible tradition. Once they believe she deserves to be killed, this is what is done,'' Deeb added. ''She was killed because she is a woman, plain and simple.''

In Rameh, a village of some 5,000 Muslim, Christian and Druse Arabs, few loudly condemned the murder.

When about 100 men and women demonstrated to protest the death a week later, Rameh men called them whores, beat them, and ripped their signs. Five demonstrators and five village men were arrested.

Still, organizers called the protest a success and noted that for the first time there was some public move against an honor killing. ''This is progress, however slow,'' said Janan Abdu-Haloul of Woman to Woman.