LAST April, when a militant group of Jewish settlers suddenly descended on this rocky hillside, the name they chose for their town gave a clear indication of their intentions. "Revava" comes from the Jewish equivalent of the blessing "be fruitful and multiply."On the morning after its overnight appearance, Revava consisted of 14 mobile homes perched on a boulder-strewn patch of earth. As seven families moved their first belongings into their new homes, bulldozers roared around the site, leveling more land. Today, six months later, the settlement has grown to more than 30 flat-roofed trailer homes, and 21 families live here. Realizing the worst fears of Palestinians who are watching their hold on the occupied territories erode, the bulldozers are still at work, expanding Revava's borders yet further into a landscape dotted with olive trees. Neat concrete and tarmac paths have been laid between the mobile homes, and electricity poles march from one end of the settlement to another. One trailer has been made into a synagogue, another is being used as an army outpost, and a third, with its front yard converted into a sandlot, houses a rudimentary playschool. The settlers have introduced a few suburban details. Some have covered over the newly torn up earth outside their doors with patios of paving stones, and installed garden furniture. Others have constructed tiny rock gardens, and planted them with tidy shrubs and flowers that look strangely out of place against a vista that has remained unchanged for millennia. But even as those plants put down their roots, Revava still has an air of impermanence, its grip on what was once Arab land a tenuous one. Its settlers can only dream of a future that beckons them from Ariel, another settlement just five miles down the road. Thirteen years ago Ariel made an even more tentative start than Revava - two tents dropped onto a hillside from a helicopter. Today it is a flourishing township of 12,000 people, one of the fastest growing settlements in the West Bank, striding confidently along a ridge with street after street of villas and bungalows, shops and offices. There are now 143 Jewish settlements in the West Bank and Gaza Strip, housing around 100,000 people, ranging in size and sophistication from Revava to Ariel. Housing Minister Ariel Sharon, who announced yesterday that he will run for prime minister, says he plans to build 13,000 new homes in the territories over the next two years, to attract another 50,000 settlers. At the edge of Ariel dozens of apartment blocks are going up, and most of the 1,200 unfinished homes have already been bought. Ariel's planners have given permission for another 3,000 units to be built next year. In the shopping center, crowded with computer stores and cafes and supermarkets, real estate agents are doing a booming business. Cards in one window advertise vacant homes in Russian (10 percent of Ariel's inhabitants are new Soviet immigrants), and at another a big sign welcomes prospective buyers in Spanish. Ariel's horizons have stretched worldwide, and with success. Alice Moran came here from France last year because by settling in the occupied territories she wanted to act on her belief in a "Greater Israel." "We are not occupying this land," she argues. "We are returning to it." Nor are Ariel's residents contemplating leaving, as Middle Eastern leaders prepare for a peace conference later this month that the Palestinians hope will return the occupied territories to their control. One student, registering this week for the academic year at the brand new, sprawling campus that Tel Aviv's Bar Illan University is opening here, laughed scornfully at a question about her future studies if Israel were to withdraw from the West Bank. "We'll never do it," she said firmly. "This place is ours, just look," she added, gesturing at the streets of houses around her. In Ariel, the newest symbol of the town's faith in its future is a luxury hotel, complete with swimming pool and artificial waterfall. Around the lobby, full of potted palms and minimalist furniture, shops are being fitted out. Three have already opened. Two of them are boutiques. The third is a realtor.