It is increasingly clear that the administration of Prime Minister Fouad Siniora is the government of Lebanon in name only. In deciding to confront Hezbollah last week, Mr. Siniora badly miscalculated, and was forced to make a humiliating retreat. Now, the country teeters on the precipice of a civil war, with Hezbollah and its Iranian backers poised to make more gains in the volatile Middle East. There is little indication that this dynamic can be stopped, much less reversed.

Hezbollah has slowly accumulated power in Lebanon. A 15-year civil war, a tense and sometimes explosive standoff with Israel, fractious and violent domestic politics, and the failure of the Beirut government to meet the rudimentary needs of Lebanese citizens, all created a vacuum that Hezbollah, a militant Islamic group supported by Iran and Syria, has managed to fill. Hezbollah's ability to battle Israel to a draw in 2006 boosted its prestige in the country and the region to the point where it has emerged as a credible challenger to Mr. Siniora's own power and authority.

The extent of its strength was made plain last week when the Beirut government decided to dismantle Hezbollah's private telecommunications and to fire the head of security at Beirut's airport, an ally of Hezbollah. While it is not clear why the government moved against the group now, it has been reported that security officials discovered that Hezbollah was using a camera to monitor takeoffs and arrivals at the airport and the security chief refused to dismantle it when told.