Washington — The Middle East certainly cannot be equated with the United States domestic political arena. Yet the pro-Israel sentiment within the US Jewish community is something that American politicians, particularly presidents, are always aware of. This year, because of a mixed reaction among American Jews to the Israeli actions in Lebanon, the US political climate is just a little different than usual.
Political candidates in areas with sizable numbers of Jewish-Americans find that they can criticize Mr. Begin's initiatives without feeling they might incur blanket disapproval at the polls this fall from Jewish voters.
What is particularly noticeable is a new political mood in the Reagan administration toward Israel. The President has always dealt with US Jewish leaders with kid gloves. In fact, during the 1980 campaign his warmth toward Israel was such that he cut deeply into the Jewish vote that normally goes to the Democratic presidential nominee.
But now a new political judgment has been made among Reagan's advisers - and endorsed by the President: that he now can pursue an evenhanded course in the Mideast without the risk of paying a heavy toll in the fall elections.
This judgment in no way means the President would turn his back on Israel and on his often expressed pledge to guarantee its existence as a nation. Nor does it mean any tilting toward the Arab states.
But the President does see an opportunity now to press for some progress toward settling the Palestinian problem. And, his associates say, Mr. Reagan intends to give it his best shot in trying to achieve this goal.
The President has no intention of dealing with the Palestinian Liberation Organization unless he receives what he regards as an acceptable commitment to recognize Israel. Yet he intends to continue probing and listening in an effort to foster an accommodation between Israel and the PLO.
This new mood is already being sensed by the Israelis. The President is being exceedingly firm in his private talks with Israeli leaders, including Prime Minister Begin and Foreign Minister Yitzhak Shamir. He is telling them in no uncertain terms that he wants an end to the siege of Beirut. But more than anything he is expressing his displeasure over Israel's use of US arms in military action that many Americans now feel is no longer simply for defensive purposes.
What the President wants to avoid - and this, too, he is telling Israeli leaders - is a new Mideast context in which resolution of the problem of a Palestinian homeland becomes even more remote than it is today. On this count the President is understood to be adding this specific: he wants the Israelis out of Lebanon and quickly. Without this happening, the US sees little possibility of opening up any kind of negotiations relating to the Palestinians.
The President may indeed be losing some support among Jewish Americans for this new ''get-tough'' policy toward Israel. However, so far he has not felt the united wrath of what is called the pro-Israel political lobby.
Further, Reagan's political advisers are telling him that a large segment of the Jewish community, as well as many Jewish leaders, are sympathetic to a US initiative focusing on the problem of the stateless Palestinians.
But playing an important role in the President's determination to rein in the Israelis is the word from his advisers that this can be done without putting too heavy a political burden on Republicans up for election this fall.