The constant in all those disputes is the utter inability of the state to arbitrate.

“The rules are still being negotiated,” said Peter Harling, an analyst with the International Crisis Group in Damascus, Syria. “The Doha agreement was a truce and nothing more than a truce with a temporary set of rules, but fundamentally, the rules that will define the balance of forces — or the power-sharing formula, if you want — between the players in Lebanon are still being negotiated.”

Lebanon’s dysfunction is an extreme case. Its system of spoils — power divided rigidly among religious communities — offers protections to minorities but makes a sham of a broader notion of citizenship. But the failure of the state here is by no means unique. Iraq’s government, still populated by exiles who returned after the American invasion of 2003, has shown a remarkable inability to resolve that country’s most pressing questions. You only have to listen to the curses directed at it every time the electricity goes out (which is often). In Egypt after the church attack, the state television blared nationalist anthems that did little to drown out the deep frustration at a proud nation’s decline. The protests in Tunisia seemed to be a metaphor: At some point, you can only bear so much.

“Transitions are pending,” said Robert Malley, an expert on the Middle East and North Africa at the International Crisis Group in Washington. He listed the reasons for the beginning of an end: “The loss of energy, the loss of steam among many of these so-called moderate Arab countries, the loss of any purpose around which they can rally other than the simple survival of the regimes themselves.”

In a way, dynamism in the Arab world has simply gone elsewhere. It could be argued that Iran and Turkey, non-Arab states that aggressively pursue divergent aims in the Middle East, play far greater political roles in the Arab world than any single Arab state. Hassan Nasrallah, the stentorian secretary general of Hezbollah, regularly wins popularity contests in the region. (The leaders of Iran and Turkey fare well, too.)

Mr. Malley said their momentum stemmed from a sense of mission: “They do seem to have some purpose around which they are rallying.”

The miserable state of affairs in the Arab world is often seen here as the detritus of Sykes-Picot, the 1916 agreement that was the highlight of Britain’s and France’s deceitful machinations to divvy up the spoils of the Ottoman Empire after World War I. They drew borders that forged only more divisions (Lebanon), imposed monarchs where their families had no roots (Jordan and Iraq), and created a climate of conspiracy in a region where conspiracies are still hatched. The creation of Israel followed, helping give rise to Arab national-security states that claimed legitimacy through their conflict with it.

The United States is also blamed here for helping distort the more modern version of these polities, by failing to end the Arab-Israeli conflict, rejecting engagement with Islamist movements and helping prop up governments like Egypt’s and Saudi Arabia’s that seem incapable of reforming themselves. Secretary of State Hillary Rodham Clinton scolded some of those allies last week for that lack of reform, though forgoing mention that some of the most dictatorial are some of America’s closest allies.