In practical terms, the current rift between the United States and Israel does not yet amount to much. American aid and arms deliveries to Israel have not been cut off. Talks between Egypt and Israel continue. The US is still convinced that the Israelis will stick to their pledge to withdraw from the occupied Sinai in April 1982.
But, according to State Department officials, the rift is significant in psychological, political, and diplomatic terms. If it continues, it could begin to affect the prospects for the highly important Sinai withdrawal. Much will depend on whether the US sticks with its decision to suspend the recently signed agreement on strategic cooperation with Israel, whether Israel continues to engage in the harsh rhetoric which has characterized its initial reaction to the suspension, and whether Israel assumes a positive attitude in its continuing negotiations with Egypt.
In Jerusalem, Prime Minister Menahem Begin said Israel considered the US suspension of the cooperation agreement to mean that pact was being canceled. The full implications of this statement were not clear.
What is certain so far is that while the Reagan administration and Israel may agree on a number of issues related to defenses against the Soviet Union, they are not on the same wavelength when it comes to a number of regional developments. The US sees Syria as a potential participant in a comprehensive Middle East peace settlement. Prime Minister Begin - while offering to talk with Syria - appears to have almost written off that prospect.
The US wants to perpetuate the current cease-fire in Lebanon, has mixed evidence as to a Palestinian military buildup there, and wants Israel to halt any plans it might have for invading southern Lebanon. Israel, on the other hand , professes alarm over the Palestinian buildup, and, according to a senior US official, may have been planning an invasion of southern Lebanon while world attention was diverted to events in Poland.
What is certain is that trust on both sides has been badly shaken. At the outset of the Reagan administration, Prime Minister Begin acted as though this administration was the best news yet for Israel. He clearly does not think that now. Israel's bombing of an Iraqi nuclear reactor, air attack on Beirut, opposition to the Saudi AWACS sale, and annexation of the Golan Heights have changed the Reagan administration's view of Prime Minister Begin.
In practical terms, the strategic cooperation agreement had not yet amounted to a great deal. It had yet to be fleshed out. Signed on Nov. 30 by Israel's defense minister, Ariel Sharon, and US Secretary of Defense Caspar W. Weinberger , it provided for US-Israeli cooperation in countering the Soviet Union. But it fell short of what the Israelis wanted.
The agreement meant - potentially at least - that the US might buy up to $200 million worth of Israeli military supplies. That is not a large amount when one compares it with the billions in aid which the United States pours into Israel.
Appearing on the CBS television program ''Face the Nation'' on Dec. 20, Secretary of State Alexander M. Haig Jr. called in effect for a cooling off of the tough rhetoric from both sides.
''The time has come now for the leadership in both countries to get to work to repair this damage. . . . And above all to continue with the peace process,'' he said.
Haig said he anticipated that Israel will ''live religiously'' by the obligations of the Camp David accords, will return Sinai on schedule, will continue as an ''active and cooperative'' member of the talks with Egypt on Palestinian ''autonomy.''
''I am very optimistic that today's storm clouds will pass. . .,'' said Haig.