AS United States Secretary of State James Baker III arrived here Oct. 16 to finish preparations for the proposed Middle East peace conference, right-wing Israelis opposed to any negotiations were planning a stormy welcome for him."Go home, Baker, Israel's not for sale," blared a poster plastered around the Jewish quarter of Jerusalem's old city by the settler movement Gush Emunim. Illustrating the hysteria that has gripped some extremist groups, a graffiti artist had emphasized one poster's message even more strongly - the US envoy had a Hitlerite haircut and toothbrush moustache. As the prospects for a peace conference have mounted, so too have fears among right-wing forces both inside and outside the government that the US intends to force Israel into concessions to its Arab neighbors that would amount to a sellout. Science and Energy Minister Yuval Neeman, head of the extreme right-wing Tehiya (Renaissance) Party, has suggested half facetiously that the peace conference be held in Munich to underline the dangers of appeasement. But Prime Minister Yitzhak Shamir's apparent readiness to attend the conference, subject to certain conditions, has posed a dilemma for the three small right- wing parties that ensure Mr. Shamir his parliamentary majority: How far to press their opposition to peace talks? Tehiya, the most vocal group, proved unable to decide at a meeting of its leaders Oct. 13 whether and how to withdraw from the government. The party's central committee split between proponents of an immediate pullout and supporters of Mr. Neeman, who favors staying in unless Israel begins to negotiate a "land-for-peace" deal with its neighbors. Divisions over the issue were highlighted Oct. 14, when Tehiya members of the Knesset (parliament) abstained from a vote of no confidence, ultimately unsuccessful, sponsored by the Labor Party. That abstention, says political analyst Naomi Chazam, a professor at Hebrew University, "means they are basically undecided. Their guiding principle is that they have no interest in going to a peace conference, but they don't want to totally lose their entree to power." If Tehiya and its two sister parties on the extreme right, Moledet and Tzomet, were to withdraw from the government, their seven members of the Knesset could deny Shamir his narrow majority, currently 65 in the 120-member parliament. Such a development, however, would not necessarily lead to a government collapse, since Shamir could run a minority government should he so choose. Only if his Likud government lost a vote of no confidence in the Knesset would he be forced to call early elections, and the Labor party has promised to prop the government up in order to keep the peace process alive. "We have offered a security net," says Labor Knesset member Shimon Shitreet. Deprived of a day-to-day parliamentary majority, Shamir might decide he could no longer govern, and call elections at a date of his choosing. But only if an election campaign were guaranteed to stall the peace process would this suit the right-wing parties' purposes, Mr. Shitreet points out. Mr. Baker suggested recently he would not regard elections in Israel as a reason to hold up the peace talks, since the current government would still be in office until the vote. At the same time, worries Eden Blitental, spokesman for Moledet leader Rehavam Zeevi, the right- wing parties do not want to give the opposition Labor Party an opportunity to form a government in coalition with religious parties that a government collapse now would offer. Meanwhile, Shamir's preparations for the peace conference have sparked challenges from within his own Likud party. Housing Minister Ariel Sharon, a vociferous hawk, announced last week he would stand against Shamir for their party's nomination as prime minister at the next national elections.