As a result, Washington’s Lebanese allies found themselves with a gun to their heads. Recognizing that the Bush administration was unwilling to back them with force, they began to compromise and move toward reconciliation with Syria, which backs Hezbollah. Even Prime Minister Saad Hariri, who once led the charge against Syria, is now bowing to political reality and has been to Damascus, Syria’s capital, four times in the past year.

The Lebanese Army, meanwhile, has been so intent on preserving its status as the country’s one neutral institution that it is now largely impotent. During the fighting in May 2008, for instance, soldiers sat in their American Humvees and watched, unwilling to take sides.

That led some Israel-friendly members of Congress to question the usefulness of aiding Lebanon’s military. When the border skirmish took place this month, some American lawmakers went further and echoed what Israeli officials were saying: that Hezbollah’s growing power in Lebanon seemed to be extending to control over the army.

There is little evidence of that. The army is still largely commanded by Christian generals who were trained in the United States. Like Lebanon itself, the army contains a mosaic of political affiliations. What American politicians often fail to understand is that even pro-Western Lebanese tend to regard Israel — which has repeatedly invaded and bombed its northern neighbor — as a hostile force. Soldiers in southern Lebanon are authorized to open fire if they see violations of the United Nations cease-fire that ended the 2006 war.

Another point often overlooked in the West is that the army’s mere presence in southern Lebanon is a novelty. Troops were deployed there — with Hezbollah’s permission — under the terms of the cease-fire brokered by the United Nations in 2006. It was the first time that Lebanese soldiers had defended the southern border in decades, thanks to the disruptions of Lebanon’s 15-year civil war and the long Syrian military occupation.