Finding a way out of the carnage that has devastated Syria takes more than a promise. Russia and the US did that in brokering the most recent ceasefire as a lead-in to a new attempt at peace talks, but as in the past, guns, bombs and bickering led to its collapse. The deadly airstrike last Monday on a UN aid convoy, a day after an admitted accidental American raid that killed Syrian soldiers, prompted emergency talks of diplomats in New York on Thursday that quickly broke down. But if the major powers involved in the conflict were earlier able to overcome differences to strike a deal, they owe it to the nation and its people to push ahead with the search for a solution.

The relationship between Moscow and Washington is riven by decades of mistrust. Syria amplifies differences, with Russia militarily and politically supporting Syrian President Bashar al-Assad in the civil war against rebel groups and the US seeking his removal for democratic elections. Finger-pointing was therefore inevitable when the Red Crescent trucks carrying UN food and medicine supplies to a rebel-held area near Aleppo were attacked; both nations blamed each other, contending respective fighter jets had been in the vicinity. But the response to such an atrocity should be condemnation and a vow to investigate, not accusations. Syria has ignored all and launched its heaviest offensive in months against opponents in the city.

Complicating matters is the role of allies and regional powers, their motivation largely self-interest rather than seeking peace. Russia has gained access to a strategic Mediterranean port, the US is assuring its regional military foothold, Turkey’s focus is on undermining Kurdish aspirations, Iran is striving to strengthen its links to Hezbollah in Lebanon and Saudi Arabia wants to limit Tehran’s regional influence. Their involvement includes providing weapons and funding to allied fighters.