Many are the regional and international parties involved in the conflict in Syria, yet only two seem capable of making big decisions. On Sept. 10, Russia and the United States reached a tentative agreement for a cease-fire in Syria, imposing full adherence on all involved parties. However, the truce came to an end Sept. 19 as both Washington and Moscow exchanged allegations of noncompliance. Russia raised questions over the Sept. 17 American-led air raid that reportedly killed at least 62 Syrian soldiers in Deir Ez-Zor, suggesting that it might leave the whole peace process in tatters. Meanwhile, the United States held Russia fully responsible for the attack on a United Nations aid convoy near Aleppo by the Syrian air force Sept. 19.

There was much hope that Russia and the United States could show more compliance with the agreement to help move toward a new level of understanding — a milestone that might facilitate a comprehensive peace plan to end almost six bloody years of a conflict that has claimed the lives of hundreds of thousands and driven more than half of Syria’s population from their homes. Such a goal couldn’t be fulfilled without the help of two other main regional players, Iran and Turkey — both of which have military presences in Syria and strong influence on militants fighting on opposite sides of the conflict.

“There’s no reason to believe the Americans. It’s only because of our Russian ally that we are ready to cooperate,” an Iranian military source told Al-Monitor on condition of anonymity. “To secure this truce, there were men fighting and dying in Aleppo and they helped make it happen,” said the source. Iran’s official stance, as expressed by Foreign Ministry Spokesman Bahram Ghasemi, welcomed the US-Russia deal. On Sept. 11, Ghasemi told reporters in Tehran, “Iran has always welcomed a cease-fire in Syria and the facilitation of humanitarian access to all people in this country.” He added, “The cease-fire needs to be sustainable and enforceable, not providing the terrorists with any opportunity to beef up [their forces] and [re-equip].”

Iran is always cautious when dealing with these kinds of situations. Indeed, one previous experience was bloody enough to raise concerns. The Khan Touman battle on May 6, following the Feb. 27 cease-fire, saw dozens of soldiers fighting under Iranian command being ambushed, killed and some captured. Back then, Iranian officials thought that the cease-fire was “merely an opportunity for the recruitment and reinvigoration of the terrorist groups by the governments that support them.”