Syria crisis: What's behind the fresh diplomatic push?
The last few weeks have seen intense diplomacy between Iran, Saudi Arabia, the United States and Russia, in what seems to be a concerted effort to break the logjam over the Syrian conflict.
The multi-faceted civil war has lasted over four years, killed more than a quarter of a million people and dislodged upwards of 10 million, in what is being seen as the worst refugee crisis for half a century.
Some of the meetings have been rare or unprecedented:
- In Doha, three-way talks on Syria between the US, Russian and Saudi foreign ministers
- A rare trip to Oman by the Syrian foreign minister, who also shuttled to Tehran to meet top Iranian and Russian officials
- In Riyadh, reports of a low-key but groundbreaking meeting between top Syrian and Saudi intelligence officials
- To Moscow, a stream of rather more high-profile visitors, from the Saudi foreign minister to various Syrian opposition members
- A tour by the Iranian foreign minister through Middle Eastern and South Asian capitals to promote a new peace plan which Tehran says it will take to the United Nations
There is no sense yet that any of this is heading for a breakthrough. But for top diplomats focused on the Syrian crisis it seems there has been no time for a summer holiday.
So what is driving this flurry of activity?
In the first place, the recent nuclear deal with Iran struck by global powers has created new diplomatic momentum and led to all sorts of jockeying for position.
Now that Iran is coming in from the cold, it is impatient to assert itself as the leading Shia country in the Middle East and the key interlocutor in any Syrian peace deal.
This has alarmed its main Sunni rival. The Saudi Kingdom is wary of Iran's new prominence and its closer relations with Washington.
So the Saudis are reaching out to Russia as a counterweight, in part to show the Americans that they can no longer take Saudi loyalty for granted, in part to challenge Iran's claim to regional primacy.
The Russians are also worried about a new US-Iranian axis.
President Putin is always on the lookout for ways to teach the Americans that they are not the only game in town.
So reaching out to the Saudis, while also fostering links with Iran and trying to cajole Syria's fragmented opposition into talking to Damascus, is part of Moscow's attempt to take on the mantle of the key international mediator when it comes to Syria.
Meanwhile, the Americans want to see whether the Iran nuclear deal can both unlock the Syria conundrum and strengthen other relationships - with both Tehran and with Moscow.
Western diplomats say that despite bitter differences over Ukraine, the Russians remained largely helpful when it came to the Iran nuclear talks.
So could common concerns over Syria help the West to mend fences with Russia?
Which brings us to the second reason why diplomacy is back in the air: the rise of so-called Islamic State (IS) jihadists in both Syria and Iraq.
The urgent need to counter the rise of IS is something which all these big powers can agree upon.
Iran is desperate to see the IS threat removed or contained. It disrupts the conduit route to its Hezbollah Shia allies in Lebanon.
It challenges Iranian interests in Iraq, where IS may hold sway over as much as a third of the territory. It is an existential threat to the weakening power of Iran's ally in Syria, President Assad.
As the so-called IS caliphate has spread its tentacles across the Middle East and beyond, staging terrorist attacks in Saudi Arabia, in Turkey and Western Europe, it has gone from being a regional to a global threat.
The Kremlin, too, is seriously worried. Already IS jihadists are enlisting recruits in Russia: what if they reactivate a bombing campaign to threaten the safety of Russian citizens?
Setbacks for Assad
On the ground in Syria too, all these countries have reason to be alarmed.
Iran and Russia have watched as the influence and reach of their client, President Assad, has been steadily eroded.
He still controls the capital Damascus and towns in the Western part of the country.
But he has suffered a series of military setbacks at the hands of IS and other insurgent forces.
Just in the last few days he announced his troops in north-west Syria were pulling back to a new defensive line around his Alawite homeland.
Meanwhile, the US and its Gulf allies must be debating whether their strategy against IS in Syria and Iraq is working.
An international coalition led by the US (and now enjoying new support from Turkey) continues to pound IS targets from the air.
But the damage which air strikes can do is limited. And proxy ground forces, opposed to both Assad and IS and in tune with Western interests, are too weak to make much difference.
So although the US and its partners might welcome the weakening of the Assad regime, the erosion of its power is also a concern.
If the Assad government were to collapse altogether then a frightening prospect of general chaos looms. That might allow IS jihadists to extend their grip over the whole country.
That is a nightmare scenario which in theory should unite the US, the Saudis, Iran and Russia.
It is almost certainly what is fuelling their latest fevered diplomatic consultations.
The problem is, when it comes to a political solution to Syria, old rifts over what to do about President Assad remain wide open.
Iran and Russia argue that he should be a legitimate partner in the fight against IS extremists.
But the West and Saudi Arabia insist that he's part of the problem, not the solution.
Possibly there are hints that the two opposing sides are inching towards each other. Russia continues to insist that its support is not for President Assad himself, but for Syria's legitimate government.
The US and other Western partners no longer declaim that "Assad must go" before there is a political settlement.
But any viable "grand bargain" looks to be a long way off. And meanwhile those fighting to seize territory on the ground are not party to any of this diplomacy.
So the big question is: can slow diplomacy move fast enough to prevent Syria from imploding into total anarchy - over which the outside world would have no influence?