Shortly after a Gaza ceasefire went into effect between Israel and the Islamic group Hamas, President Barack Obama sent his Middle East envoy to the region to kick-start a process to end the decades-long Palestinian-Israeli conflict.
The effort will focus on the so-called "two-state solution," which would establish a Palestinian state in the West Bank and Gaza Strip coexisting peacefully alongside the Jewish state.
"Lasting peace requires more than a long cease-fire, and that's why I will sustain an active commitment to seek two states living side by side in peace and security," Obama said.
Obama sent his special envoy, former Senator George Mitchell, to the region for talks with Arab and Israeli leaders. In Jerusalem, Mitchell said reaching a peace agreement will be tough.
"The tragic violence in Gaza and in southern Israel offers a sober reminder of the very serious and difficult challenges and, unfortunately, the setbacks that will come."
Jewish settlements in the occupied West Bank constitute one of the toughest problems on the way to peace.
Some 200 thousand Jewish settlers live there. Most would have to be relocated in Israel proper, under the usual view of the two-state solution.
But Israeli attempts to evacuate some small settlements have sparked violence between Israeli troops and settlers who refuse to leave.
Prime Minister Ehud Olmert has said Israel is willing to remove 60 thousand West Bank settlers for peace, a small fraction.
Israeli elections in February could make Likud leader Benjamin Netanyahu the next prime minister. He says he will not ask any settlers to leave the West Bank. In November, he suggested he is not for a two-state solution.
"I think that rather than build peace exclusively from the top down with political agreements, we have to add to the political process building peace from the bottom up by making the lives of our Palestinian neighbors a lot better so they have a stake in peace," Netanyahu said.
James Zogby is president of the Arab American Institute in Washington. He says Obama must be tough with Israel on West Bank settlement and the continuing occupation if a solution is to be found.
"Certainly, they [the Israelis] are not going to move unless they are moved, and they are not going to be moved unless the U.S. president says, 'This must end,'" Zogby said.
On the Palestinian side, there are also problems. Palestinians are divided between Fatah, the moderate faction running the West Bank, and Hamas, the militant group that rules in Gaza and refuses to renounce violence. Israel and the United States refuse to engage with Hamas.
Many Israelis and Palestinians are now questioning whether the two-state solution is still possible.
Ali Abu Minnah is a Palestinian author living in Chicago. He advocates a one-state solution, in other words, a bi-national state.
"The two-state solution is neither available nor stable nor just, and this is why we have opened the discussion," he said.
A one-state solution is rejected by Israel because Jews would soon become a minority.
William Quandt worked in the Carter administration in the 1970s and was involved in negotiations that led to the Egyptian-Israeli Peace Treaty of 1979. He says the two-state solution is the only hope.
"I think the two-state solution comes back into focus for us because there is no good alternative in terms of a negotiated solution," the University of Virginia professor said.
Zogby says Arab states should help with reconstruction in the Gaza Strip and with Palestinian nation building, and also offer Israel incentives for peace.
As Mitchell himself made clear, the task will neither be easy, nor will progress happen overnight.
But the new U.S. administration seems engaged where the previous one was not.