BEGIN TAKES OFFICE AFTER 8‐HOUR DEBATE
June 21: Menahem Begin says upon becoming Prime Min that prevention of another war is his primary concern; calls on Hussein, Sadat and Assad to meet with him in order to discuss peace; omits in speech his earlier position that West Bank is non-negotiable during peace talks; says he will endeavor to deepen Israeli-US friendship, work for renewal of close ties between Israel and France and seek to normalize Israeli-Soviet relations; Labor Party leader Shimon Peres says Begin's 'intransigent' foreign policy will cause rifts with Israel's allies; Begin illus (M)