Washington - Asked to describe the current shape of the Middle East, a visiting Israeli official uses a Hebrew expression, "gam vegam", which translates roughly to: "It's going in both directions at once."

The shards of the Middle East mosaic are as sharp and dangerous as ever, but U.S., Israeli, and Arab officials say these pieces have been rearranged in the past few months - and may now fit together in different and often surprising ways. There are opportunities few observers would have expected, and also new perils.

President Obama is often seen as a lame duck who is hobbling off the Middle East stage in his final 10 months as president. But the pace is likely to be set largely by Secretary of State John Kerry, a man who still has something to prove as a diplomat.

However the next months unfold, 2016 will shape the options for the next president. The departing Obama, who hoped to change the strategic balance in the Middle East, has partly done that - encouraging others to take a larger military role, for better or worse, but preserving U.S. diplomacy.

What are the new puzzle pieces? First, there's Syria, arguably Obama's greatest foreign policy failure. Despite a chorus of naysayers, Kerry has managed to cajole the various Syria antagonists - Russia, Iran, Turkey, Saudi Arabia, Jordan, the regime of Bashar al-Assad, the fractious opposition - into the same tent to work on details of a cease-fire.

This diplomatic process is fragile, and dependent on the goodwill of Russians and others who in the past have displayed only naked self-interest. But it's not nothing. According to State Department estimates, relief convoys have reached 225,000 desperate Syrians in the past few weeks; the target is to provide aid to 1.7 million by the end of March.

The cease-fire process invites violations, because many of the more than 100 rebel groups that have accepted the truce are camped alongside excluded fighters from the Islamic State and Jabhat al-Nusra. State Department officials describe this co-location of groups as "marbling," and expect it will take weeks for fighters to vote with their feet which side of the line they're on. This sorting will work only if there's some sign of progress toward an eventual political transition away from Assad.

Iran is the second puzzle piece that looks different than most would have predicted a few years ago. Obama's bet that Iran could be pressured into a meaningful nuclear deal by a global sanctions coalition has proved correct. What's more, his hope that the Iran opening would strengthen pragmatic forces there also appears to have borne fruit after last Friday's elections.

State Department officials say it's impossible now to calculate precisely what the political balance will be in the new parliament or the "Assembly of Experts" group that will choose Iran's next leader. But it's clear that the hard-liners have been weakened, and that President Hassan Rouhani's position is stronger. That was Obama's biggest strategic gamble; it appears to be paying off.

Saudi Arabia is also changing shape. Who would have predicted a few years ago that the decisive figure in this once-moribund, hyper-conservative monarchy would be a headstrong 30-year-old whose goal appears to be a Saudi version of the modernizing, relatively tolerant United Arab Emirates? But that's what's happening under Deputy Crown Prince Mohammed bin Salman.

The young Saudi has sometimes been more bold than wise, as in his war in Yemen, his decision to break diplomatic relations with Iran and his new effort to destabilize a Hezbollah-dominated Lebanon. But his role as a change agent is unmistakable. He "wants to transition Saudi Arabia very quickly," said Adel Al Toraifi, the Saudi information minister, who's just 36 himself, in a visit to Washington last week.

The piece of the Middle East puzzle that seems most jagged right now is Turkey, only a decade ago the brightest spot in the region. President Recep Tayyip Erdogan's power plays have shattered a once-promising reconciliation with the Kurds and undermined Turkish democracy. Turkey has managed simultaneously to worsen its relations with Russia, Israel, Iran and the U.S. - quite a feat. Veteran Turkey-watchers fear growing internal turmoil there.

As America has stepped back in the Middle East during Obama's presidency, Russia, Iran, the Islamic State and Saudi Arabia have stepped forward. This has brought many new dangers. But even though America's military dominance has faded, its diplomatic role remains decisive - as the Syria and Iran talks show.

Fitting the altered pieces of the puzzle together brings many risks, but it does provide new openings. And it's clear that even in its diminished role, the U.S. remains the indispensable stabilizing power, like it or not.

(c) 2016, Washington Post Writers Group