A war that has seesawed wildly over the past year and is now threatening to draw in other regional players is likely to pivot unpredictably many more times before it is over. Events such as the bombings that killed at least 40 people in a Turkish border town Saturday, Israel’s airstrikes against Damascus last weekend and decisions by outside powers to arm the rebels are among the many variables that could tilt the balance again.

Hezbollah no longer attempts to hide its involvement in the Syrian conflict, however. In comments quoted by the pro-Hezbollah newspaper al-Akhbar last week, Assad acknowledged his debt to the movement, expressing “very high confidence, great satisfaction and appreciation toward Hezbollah” and promising to “give them everything.”

Hezbollah leader Hasan Nasrallah has portrayed the movement’s involvement in the Syrian war as a struggle for the survival of Shiites regionwide against a rising tide of Sunni extremism. Israel’s airstrikes have further helped the movement justify its participation, said Mohammed Obeid, a Lebanese political analyst with close ties to Hezbollah, by enabling its leadership to also cast the fight in Syria as an extension of its war against Israel.

“After the Israeli strikes, Hezbollah can say openly that it is fighting Israel in Syria,” he said. “These strikes served Hezbollah and strengthened its logic.