The clock is ticking on Iran
"I will be in touch soon," was how EU foreign policy chief Catherine Ashton described her next contact with Iran after talks in Almaty ended without even an agreement to meet again.
But can it be soon enough to ease growing anxiety over Iran's nuclear programme and stave off more crippling sanctions?
"Another failed diplomatic foray is likely to prolong the standoff and increase the price each side has to pay for a compromise," commented Ali Vaez, senior Iran analyst at the International Crisis Group (ICG), who was in Almaty.
The only common ground between Iran and six world powers seemed to be recognition of how far they still have to go to negotiate a way out of this crisis.
Time is not on their side. US Secretary of State John Kerry, now visiting the region, warned talks cannot last forever.
"There are four lanes, each with a different clock," commented another long-time observer of these tortuous talks.
He pointed to the speed of Iran's nuclear work, Israeli military threats, and deepening sanctions, alongside the negotiations.
On the negotiating track, the lane is still open.
"We're hopeful that P5+1 and Iran will meet again to resume our dialogue," said a senior US official in Almaty, referring to the five permanent members of the Security Council, plus Germany, tasked with the nuclear file.
The official didn't rule out another round before Iran's presidential election in June.
And it's also clear that, in this latest round, there was more talking in the talks than ever before.
"My colleagues, some of whom have been doing this for a decade, had never seen anything quite like it," remarked a senior American official. "Rather than stilted and overly formal exchanges we had an intensive dialogue on key issues."
But what world powers didn't get was what they say they need to make any progress: a concrete, comprehensive Iranian response to their "fair and balanced" package first put on the table in Almaty in February.
It puts the onus on Iran to take the first confidence-building step. That's reported to include a six month suspension of the 20% uranium enrichment programme regarded as dangerous. Incentives include modest relief from sanctions.
But Iran's chief negotiator, Saeed Jalili, insisted: "Confidence building is a two-way street."
Too little trust
Sources say Iran is ready to stop 20% enrichment but only in return for a full lifting of sanctions. That's a step the international community won't take.
Conversations with Iranian officials also underscore their demand for a clearer sense of the "end game".
What will be the final shape of Iran's nuclear programme and the scale of sanctions if it halts some of its most sensitive nuclear work?
Essential for Iran is recognition of what it regards as its "inalienable right" to enrich uranium, enshrined under the Nuclear Non Proliferation (NPT) treaty.
Western diplomats disagree with Iran's interpretation. They also point out that the International Atomic Energy Agency (IAEA) would have to certify that Iran's nuclear programme is entirely peaceful, which it has so far been unable to do.
On both sides, there is still too little trust and too much inflexibility.
"The structure of the P5+1 deal makes a deal almost impossible," commented one informed observer in Almaty who said Iran could not work with the proposed sequence of steps.
One Western diplomat admitted as much to me.
"Iran's delegation can't go home and say it is a good offer," said the diplomat.
"Dr Jalili may want a deal but it's Iran's spiritual leader Ayatollah Ali Khamenei who calls the shots," he remarked with frustration, describing negotiations as "political theatre".
In this play, both sides read from a different script.
Playing to a domestic audience, Dr Jalili said the P5+1 had to return to their respective capitals to evaluate "Iran's proposed plan", implying the ball was now in the other court.
A senior US official said "All of us need to evaluate what the next steps should be in this process and think through how we can move more effectively to get there."
Some observers hold out hope that Iran may come forward with new ideas after its critical elections are over.
But no matter how diligent diplomats are, the clocks are also ticking on the other lanes.
Israel holding fire
"The time has come," said a statement from Israel's Minister of Strategic Affairs, Yuval Steinitz, "for the world to take a more assertive stand and make it unequivocally clear to the Iranians that the negotiations games have run their course."
Both Western and Israeli sources say Israel is holding fire, at the moment, aside from its verbal barrage.
And one Western official said Tehran was, for now, being "very careful" in its nuclear programme. It recently confirmed it had resumed the conversion of medium enriched uranium into oxide fuel to slow down growth of its stockpile.
On the sanctions front, more penalties are pending.
"The US president can't push back sanctions when diplomacy is going nowhere," emphasised Ali Vaez of the ICG.
But world powers, bitterly opposed on key crises like Syria, are still finding enough common ground when it comes to Iran.
Russia's chief negotiator, Sergei Ryabkov, spoke of being "still on the threshold" in remarks to the Interfax news agency.
"There may not have been a breakthrough but there was also no breakdown," was how a senior US official summed it up.
But without a break in the stubborn deadlock, pressure will mount, surely and steadily, on all fronts.