The Israeli government is worried that the Obama administration has decided not to block attempts to recognise an independent Palestinian state at the United Nations General Assembly in September.
Israel has yet to receive any assurances from the Americans that they will block such an attempt. Prime Minister Binyamin Netanyahu is concerned that UN recognition will leave Israel with no bargaining positions.
"Even when the relations between Jerusalem and Washington are less than great," said an Israeli diplomat this week, "we can almost always rely on the Americans to help us out with the more awkward UN resolutions. This time, we just have not got any answer out of them as to what they are preparing to do. It's as if Obama enjoys seeing Netanyahu squirm."
Although it is well known that Mr Obama is reluctant to toughen the US stance towards Israel, particularly with presidential elections on the horizon, concern over his position is not confined to diplomats in Israel. Defence Minister Ehud Barak has recently warned of a "diplomatic tsunami", a diplomatic tidal wave that will hit Israel if a breakthrough is not achieved in the blocked peace process.
Mr Netanyahu, who visited German Chancellor Angela Merkel last week in Berlin, came away with the clear feeling that the Germans - along with other EU governments - are planning to present a peace proposal which will be based on a Palestinian state on the 1967 lines with East Jerusalem as the Palestinian capital.
If the EU, along with the other Quartet, the United States, the UN and Russia, adopt such a plan, argue Mr Netanyahu's aides, Israel will have no power to negotiate on other matters such as security arrangements and the return of Palestinian refugees.
The Israeli government has embarked on a number of diplomatic initiatives to try to convince the Western governments not to support recognition of a Palestinian state. On the one hand, Israeli diplomats have warned of "unilateral steps" that Israel will be forced to take. These are assumed to include the annexation of part of the West Bank to Israel. On the other hand, Mr Netanyahu is considering allowing the PA to take control over larger areas of the West Bank than the eight cities which it currently rules.
While Mr Netanyahu has already been attacked by the settlers and the right-wingers in his government for his apparent willingness to accede Israeli control over further parts of the West Bank, it does not seem as if any of these proposals will convince the Palestinians to relinquish their attempts to gain UN recognition in September.
This week the PA was further emboldened by a UN report which concluded that the authority is able to run a state and that the main obstacle is the Israeli occupation. Further encouragement could be found in a report delivered by the Quartet's special envoy, Tony Blair, to a meeting of the nations donating to the Palestinian Authority. The report endorsed the calls for the foundation of an independent Palestinian state.