Beirut — ''At least there will be one less tyrant in the world now,'' commented a former Lebanese prime minister on hearing the news of Israeli Prime Minister Menachem Begin's plans to resign.
But he hastily cautioned: ''We should not rejoice too much about this. There is no reason to think things will change.''
It was one of the milder reactions in the Arab world. Perhaps no Israeli leader has been so feared by Arabs, both because of his tough policies as Israel's recent leader and because of his past association with Jewish insurgents in the days of British Palestine.
Mr. Begin is held responsible for some of the greatest Arab humiliations: the bombing of the Iraqi nuclear reactor near Baghdad, two invasions of Lebanon, the annexation of the Golan Heights, and the West Bank settlements policy.
Most humiliating of all for many Arabs, however, was an act of peace - the Camp David agreement. Much of the Arab world feels that Camp David ''robbed'' it of its traditional leader, Egypt. These Arabs suspect Mr. Begin agreed to that peace treaty in order to be able to thwart peace on the broader Palestinian issue. With Egypt's political and military muscle removed from the confrontation with Israel by the peace treaty, the Arabs are divided and weakened.
And most bewildering to the 21-nation Arab bloc has been Mr. Begin's ability to lead his tiny nation in defiance of United States pressure on peace efforts, both in Lebanon and in the broader 35-year Arab-Israeli crisis.
Egypt's reaction typified that of much of the Arab world in that it was concerned more with Israel's policy than with the person in charge.
''What concerns us is that it (Begin's resignation) should not have a negative effect on the peace process,'' State Minister for Foreign Affairs Butros Ghali said, ''and that the Israeli administration should continue to maintain the necessary momentum for the achievement of a comprehensive and just peace in the region.''
State-controlled newspapers in the conservative Gulf states generally predicted that Mr. Begin's decision will not change the ''aggressive and expansionist policies'' of Israel, as one editorialized.
Indeed, the primary fear is that Israeli Foreign Minister Yitzhak Shamir will be the next premier - a man viewed with greater suspicion than was Mr. Begin.
The general Arab hope is that the Labor Party will take over the reins of power, either through elections or because the Likud is unable to agree on a new government. Arab moderates tend to favor Labor because its leadership has shown a more flexible stand on the West Bank.
The one item repeatedly stressed by Arab news outlets, particularly in Jordan and Syria, was that the Begin resignation was the result of what the Damascus paper ''Al Baath'' called ''his political failure at home.'' The reference was to Israel's troubled economy, its political squabbling, and its apparently growing anti-war sentiment.
Arabs increasingly realize that it is internal opinion, rather than outside pressure, that has the greatest impact in Israel.
Although no prominent Arab official or news outlet felt the resignation offered short term hope on peace efforts, there was cautious optimism that it might serve as a precedent; that domestic pressures might, long term, force the government into a more compromising mood of coexistence with the Arab world.