A Mennomite teacher working with Palestine Arabs took me to visit a couple of the new Israeli settlements on the west bank of the Jordan River the other day. Afterward he said: "Well, it's not exactly sunny, downtown Burbank."

That skeptical crack by an American not particularly friendly to Israel is the beginning of wisdom about the highly inflated subject of the new settlements. For they are far less fortresses of militant Israel that pathetic expressions of a dwindling idealism.

The first of the settlements we saw was Beitel, about a dozen miles from Jerusalem. Moshe Robbins, the secretary of the settlement, was loath to talk to us. With good reason.

Arabs from a nearby village claim the land on which Beitel is being built. They have pushed their claims in Israel, and the Israeli courts have taken jurisdiction. There is a chance the settlers will be forced to move by a court finding that they have no title to the land.

On top of that there is the problem of electricity. Beitel is not hooked up to the main power line that crosses the west bank from Jerusalem to Jericho. The 40 families in the settlement use portable generators. They report about three power outages a day, on the average.

Not that they are big consumers of anything. The homes are temporary prefabs, with a minimum of space. Children and parents double up in a single bedroom. A tiny kitchen, a bathroom and a combined living room-dining room make up the rest.

Settlers, not surprisingly, are not exactly lining up by the thousands to enter such accommodations. One of the sources of the settlement, the secretary did say, is the housing project of Kyrat Arba in Hebron. A foreign diplomat told me that there are 300 vacancies in the Hebron housing project. In other words, the source for settlers at Beitel is drying up.

The second settlement we visited is Ofra, a few kilometers deeper in the formerly Arab land on the west bank of the Jordan. Ofra, a far sturdier enterprise, was established three and a half years ago on the site of a former Jordanian army camp. The 50 families living there draw electricity from the power line that runs through the west bank and the local water line that runs from the Jordan to East Jerusalem.

They have established several cottage industries - cabinet-making, metal shops and silk-screen production. Though the houses are small prefabs, some of the residents are adding extra bedrooms. There is a small school and a special spirit.

"We are not a communal settlement," Menucha Nathan, the settlement secretary who comes originally from Cheyenne, Wyo., says. "Each one of the shops is owned privately. But we were all white-collar workers. We came here to extend Israel to the historic lands, and also to show the dignity of work. We believe no job is too menial. So we all take turns doing the dirty work - for instance, collecting garbage."

I asked Nathan if many other Israelis were prepared to join settlements like Ofra. She said the shortage was of money for buildings rather than of people to live in them. But I wonder. How many white-collar Israelis are burning to take jobs making cabinets? How many believe no task is too menial?

I also asked Nathan how her settlement got on with the local Arabs. She said they had nothing to do with one nearby village dominated by the Palestine Liberation Organization. Another village seems friendlier. "We have visits and take coffee," she said. "On the whole," she added, "we don't have arguments or fights. They don't spit on us or throw stones. We get on."

I asked her if she believed the settlement could continue under the system of local autonomy proposed in the Camp David accords. "I don't know what autonomy means," she said. "None of us know. If it is a just peace, we can stay. But probably it will depend on who rules at the top."

It will indeed. Perhaps some of the older settlements on the West Bank are strong enough to last. But the new settlements are tiny encampments without intrinsic staying power. Prime Minister Menahem Begin talks them up only to cover the concessions he is making right and left.

The Palestinian Arabs could sweep away most of the new settlements with ease merely by cutting off utilities or questioning ownership. All they need to do first is make something of the myriad opportunities for self-rule handed to them on a plate by the Camp David accords.

So the roars of disapproval that come from the administration, not to mention the Zeuses of the editorial pages, whenever Israeli politicians talk up the settlements seem misplaced. The indignation and exhortation should be addressed to the Palestinian Arabs. They have only to stop making again and again and again the mistake of refusing anything until they are guaranteed everything.