The third round of Geneva peace talks between the Syrian government and opposition has been suspended three days after a shaky start, underlining the mammoth challenge of putting an end to Syria's five-year war.
Riad Hijab, the opposition's High Negotiations Committee (HNC) co-ordinator, arrived in Geneva on Wednesday to give an extra weight to the troubled talks.
But comments of Russia's foreign minister Sergey Lavrov, who said Russian strikes will not cease "until we really defeat terrorist organisations like al-Nusra Front" clearly made it difficult for both the UN and Syrian opposition to press ahead.
Over the past days, Russia and the Syrian government have intensified their aerial bombardment over different parts of Syria. The opposition say they counted over 100 airstrikes on Tuesday in northern Syria, which allowed the government to retake control of two towns in Aleppo.
The UN Special Envoy for Syria Staffan de Mistura told me in an interview this week: "Every time there is a chance for negotiations, there is just the opposite happening on the ground, they are increasing their attacks... to be in a better position."
"We should be aware of it and still push forward," he said.
But 48 hours later, the optimistic diplomat was forced to call for a "temporary pause" in the talks.
Mr de Mistura has made it clear that the aim of the conference is to encourage concrete changes that will improve the lives of Syrians on the ground.
"Since I am not seeing that, I have to be honest and say with myself, it is time now to have a pause."
'No World War Three'
Teams of diplomats representing countries supporting the opposition are pushing behind the scenes in Geneva for concessions from all parties involved in the war.
But almost everyone, whether diplomats or the opposition, says it is the US which is key to success - by using its leverage on Russia.
Russia is the only world power involved in the Syrian conflict with a military base in the country - therefore it could bring exert significant pressure on the regime of Bashar al-Assad to stop the violence.
But there is a limit to what the US is prepared to do.
A senior US Department of State official told me: "We are not ready to go to World War Three to solve this."
The US, however, is spending billions of dollars in the battle against the self-proclaimed Islamic State (IS), which controls large parts of Syria.
Many Syrians feel the selective involvement of the US is hypocritical.
The US official was adamant that Secretary of State John Kerry wants to end the violence, and is determined to succeed.
But everyone here thinks the opposite. Almost at every corner, you hear the same thought: The US has handed over Syria to the Russians for free.
The Syrian government, however, puts the blame on the Saudis, the Qataris and the Turks for the failure of the talks.
Bashar al-Jaafari, the government's chief negotiator, said the opposition delegation was "instructed by its backers to make the talks fail". He described them as "irresponsible" and "uncommitted".
Riad Hijab pointed a finger in the other direction: "The one who is using chemical weapons, barrel bombs on people, who created Isis [IS] and terrorism, is known to everyone - it is the regime of Bashar al-Assad and the militias around him."
The reality is that the opposition are in the weaker position with powers behind them limiting their support, while the Syrian government is being empowered by fully-fledged support from Russia.
Although the UN Security Council has adopted resolution 2254, endorsing a road map for a peace process in Syria, there is neither an enforcement mechanism, or the power to implement it.
Mr de Mistura wants the talks to resume again end of this month and is counting on the International Syria Support Group (ISSG) meeting in Munich next week to push for further action.
Until a peace plan is reached, the world will probably continue to see dead children being pulled out of rubble and a continued flow of asylum seekers fleeing Syria.
It is the sort of despair that will lead to more anger and radicalisation, and may well increase the numbers who will join extremist groups like IS.