As US Secretary of State John Kerry returned to the Middle East last week, the American message to the Israeli and Palestinian leaders was clear: It's time to start making hard decisions.
Israeli Prime Minister Benjamin Netanyahu would likely have to recognize Israel's pre-1967 war frontier as the starting point for border talks with the Palestinians, an ideological reversal that would put him on a collision course with his hardline base.
Palestinian President Mahmoud Abbas fears he'll be pressured to recognise Israel as the homeland of the Jewish people, a step he believes would abrogate the rights of Palestinian refugees and their descendants.
Israeli-Palestinian negotiations resumed last summer, and just four months remain until a U.S.-set target date for a final agreement.
The U.S. says a Palestinian state should be established alongside Israel, with the border between them based, with some modifications, on Israel's 1967 frontier, before it captured the West Bank, Gaza Strip and east Jerusalem. The Palestinians seek all three areas for their state, but agree to minor land swaps.
Netanyahu has so far refused to accept the 1967 lines as a reference.
Doing so would imply Israeli willingness to partition Jerusalem and its sensitive religious sites, give up most of the West Bank and uproot tens of thousands of close to 600,000 Israeli settlers living on occupied land. Such ideas are anathema to Israel's right-wing, including many in Netanyahu's Likud Party.
Israel withdrew from Gaza in 2005, following a dramatic decision by Israel's most famous hawk, then-Prime Minister Ariel Sharon.
Netanyahu has sent conflicting signals, accelerating settlement plans in recent months but also telling Likud legislators that a leader is measured by his ability to make tough decisions.
Trying to divine Netanyahu's intentions has become a national obsession.
Those favouring a partition deal say Netanyahu can move forward even without the support of his political allies. Opposition lawmakers have said they would support him.
An opinion poll Wednesday indicated that a majority of Israelis and Palestinians favour a Palestinian state alongside Israel, but that support drops when respondents are given specifics to ponder.
For Abbas, the biggest concern is that he will be asked to make concessions on the fate of refugees by recognizing Israel as the Jewish homeland, his aides said. Hundreds of thousands of Palestinians fled or were expelled in the war over Israel's creation in 1948. These refugees, and their descendants, now number several million people.
The refugee issue is so charged that Palestinian leaders have largely avoided public debate on the matter, while insisting that Israel recognize at least the principle of a "right of return."
Israel has emphatically ruled out absorbing large numbers of refugees, saying this would dilute the state's Jewish majority.
Palestinians argue that recognizing Israel as a Jewish state would mean dropping the demand for a right of return and also forfeiting the rights of Israel's 1.7 million Arab citizens. The Palestinians have already recognized the state of Israel and believe this is sufficient.
John Kerry on Saturday cited progress on the Mideast peace process, yet acknowledged that some of the most intractable disputes between Israelis and Palestinians were unsolved after more than 20 rounds of negotiations.
It is unlikely that the situation which has dragged on for decades will be resolved anytime soon.