GENEVA — Russia and the United States reached agreement early today on a new plan to reduce violence in the Syria conflict that, if successful, could lead for the first time to joint military targeting by the two big powers against Islamic jihadis in Syria.
The agreement was reached after 10 months of failed cease-fires and suspended efforts for a political settlement in the Syria war, which began more than five years ago, has left nearly a half-million people dead and created a refugee crisis.
Secretary of State John Kerry and his Russian counterpart, Sergey Lavrov, announced the agreement in Geneva after weeks of negotiations that were marred, in President Barack Obama's words, by deep "mistrust" between the Russians and Americans.
The new arrangement is supposed to begin Monday in Syria, with a seven-day-long continuous "genuine reduction of violence," in Kerry's words, and broad, unrestricted humanitarian access to the ravaged northern city of Aleppo and other besieged areas.
If that works for the initial period, the United States and Russia are supposed to immediately establish a Joint Implementation Center, where they will share targeting data, and begin to bomb militants of the Nusra Front and the Islamic State.
The key element is that Russia is then supposed to restrain the forces of President Bashar Assad of Syria from conducting any air operations over Nusra and opposition areas, which the United States hopes will bring an end to the dropping of barrel bombs, including chlorine gas attacks.
In return, the United States is supposed to get the opposition groups it has been supporting to separate themselves from Nusra forces. Assad has attacked many of them on the pretense of attacking Nusra.
Kerry sounded extremely cautious about whether this new arrangement would work.
"We believe the plan, if implemented, if followed, has the ability to provide a turning point, a change," he said. Sounding far more cautious than he did in Munich, Germany, in February when he announced an earlier "cessation of hostilities" that failed, he said: "No one is basing this on trust. We are basing it on oversight and compliance."