BEIRUT — Iran's internal debate over how to address Lebanon in the wake of Israel's Sunday strike on Beirut's southern suburbs is shaping its diplomacy with Washington.

Tehran does not view the current negotiations solely through the lens of ending the war. It also sees them as helping shape Lebanon's political order once the fighting stops.

The attack on Dahiyeh sharpened longstanding divisions in Tehran between those advocating restraint and those arguing that military confrontation is the most effective way to deal with Israel. According to Iranian and regional sources familiar with the discussions, the domestic struggle has not only influenced Tehran's calculations over whether to retaliate militarily, but also shaped the terms Tehran sought in emerging understandings with the United States.

Sources familiar with indirect discussions between Tehran and Washington told Al-Monitor that Iran had completed preparations for a significant military response and that only a political decision remained. For several hours following the attack, mediators worked to prevent an escalation that could have derailed both the diplomatic track and the understandings beginning to emerge.