American diplomats have been trying this week to lower expectations over State Secretary John Kerry’s visit to Israel and Jordan starting today.

This is not the last opportunity for Israelis and Palestinians to respond to his plan for new talks, they said; he will come again in a few weeks and work things out then. But it is hard to avoid the feeling in Jerusalem and Ramallah that this will be a crucial visit, a make-or-break round of meetings in which the success of Mr Kerry’s energetic attempt to renew negotiations between the sides will be decided.

Pressure has been building on both sides for three months, since President Barack Obama’s visit to the region.

Prime Minister Benjamin Netanyahu for a few weeks now has been signalling his willingness to make concessions repeating his commitment to a two-state solution. In an interview with the Washington Post last weekend, Mr Netanyahu said that if Mr Kerry were to pitch a tent between Jerusalem and Ramallah, “I’m in the tent. And I’m committed to stay in the tent and negotiate for as long as it takes to work out a solution of peace and security between us and the Palestinians.”

Mr Netanyahu has reined in new building in Jewish settlements on the West Bank and in East Jerusalem, and agreed to release 120 prisoners — but only gradually, and after talks are resumed; not in advance as the Palestinians demand.

Palestinian President Mahmoud Abbas, according to various reports, has agreed to waive his previous preconditions of an official freeze on settlement building and that Israel commits to a two-state solution based on the pre-1967 borders. Some Palestinian spokespeople have denied that such concessions have been made, however.

Even if a schedule for talks between the two sides is agreed upon, it will only be a small and very precarious step forward.

In recent days, senior Israeli officials have been briefing that they are convinced that Mr Abbas will join talks only to leave them shortly afterwards for one reason or another.

The Palestinians are saying that Israel is interested only in talks for talks’ sake, but is not interested in reaching an agreement that will allow the establishment of a viable Palestinian state.

Even if the two leaders are sincere, it is highly questionable whether either of them has the political clout to push through a peace agreement.

Mr Netanyahu seems increasingly isolated within his coalition and even within his party, Likud, which this week elected Deputy Defence Minister Danny Danon as the president of the party’s conference, against the Prime Minister’s wishes. Mr Danon is a leading voice in Likud against a two-state solution, and reflects the majority of the party’s rank and file.

But Mr Netanyahu’s problems pale when compared to those of Mr Abbas, who has failed to achieve Palestinian unity between his party, Fatah and its Hamas rivals. Even in his own fiefdom of Ramallah, Mr Abbas seems incapable of appointing a prime minister. Any achievement this weekend by Secretary Kerry may turn out be extremely short-lived.