WASHINGTON ― The Middle East sometimes resembles a string of detonators wired to explode together ― and this seems especially true now of Syria and its neighbors. 

There is political instability nearby in Iraq, Jordan and Lebanon, as the Arab uprising moves through its second year. In each of these countries, the leadership maintains power in a balancing act. Only Turkey, with its triad of a strong economy, army and political leadership, seems genuinely stable.

Fear of blowing up the region ― and spawning even more Sunni-Shiite sectarian war ― is one reason the Obama administration has refused to arm the Syrian opposition. Officials fear that militarizing the conflict, without reliable Syrian allies or a clear endgame strategy, could produce unintended consequences much like those of the Iraq War.

Administration officials expect Kofi Annan’s peace plan will fail, but they don’t want to give up on the former U.N. secretary-general’s effort yet. Better to let the planned 300 U.N. observers travel in Syria, they reason, and perhaps encourage a new round of protest that would show that President Bashar al-Assad’s rule is doomed.

What makes this period of Arab revolution so complicated is that the new themes of liberation are becoming interwoven with ancient ethnic hatreds. Analysts from Iraq, Jordan and Lebanon describe the growing tensions in each country, as these factors play out:

― Iraq’s prime minister, Nouri al-Maliki, faces a possible breakup of his ruling coalition. The potential opposition has widened to include Moqtada al-Sadr, the Shiite militia leader, and Massoud Barzani, the Kurdish chieftain. Late last month, they threatened to dump Maliki unless he implemented a November 2010 power-sharing pact.

Sadr, the fiery cleric, was unusually blunt: “This state is under a form of dictatorship and we do not want it to remain under Premier Maliki.” When Barzani visited Washington last month, he is said to have warned administration officials, “I can’t live with another dictator in Baghdad.” Yet Maliki is still in power, thanks partly to the bizarre fact that he enjoys support from both Washington and Tehran. Symbolically, perhaps, U.S. and Iranian negotiators agreed on Baghdad as the site for nuclear negotiations taking place this week.

The old expression “once bitten, twice shy” may explain the Obama administration’s view of Iraq. The White House favors compromise with Maliki and the preservation of stability there, in part because it doesn’t want to reignite civil war in Iraq at the same time it is spreading in Syria.

― Jordan’s King Abdullah’s reign has been one long balancing act, between Palestinians and East Bankers, between secular modernizers and Islamist conservatives. He has been lucky that all sides support the Hashemite monarchy, even as they quarrel over how to divide the spoils. But lately, the political jockeying has grown more intense.

The king has burned through four prime ministers in 15 months, without getting agreement on an election law and other reforms. Corruption charges have taken down three intelligence chiefs in a row, to the point that many Jordanians wonder whether the deeper problem is in the palace itself. There is growing talk about Jordan as a staging ground for Syrian insurgents ― which might please Saudi Arabia and other Sunni powers that want to overthrow Assad, but would add new risks for the king.

― Lebanon may be in the most delicate position of all. Under Prime Minister Najib Mikati, Lebanon’s policy is “disassociation” from the Syria battle. But that middle ground is disappearing ― with anti-Assad refugees using northeastern Lebanon as a sanctuary, triggering reprisals from pro-Assad forces.

An illustration of how the regional and sectarian strands come together is the case of Shadi Mawlawi, a Sunni activist supporting the anti-Assad opposition. He was arrested two weeks ago in Beirut by the Shiite-led General Security service. According to a Lebanese official, evidence linked Mawlawi to a prominent Qatari who was funneling money to the rebels in Syria.

Mikati wants Washington’s help in keeping Lebanon from being drawn deeper into the regional turmoil, but the longer the Syria fight goes on, the harder it will be for any of the neighbors to stay out.

One wild card that could trump everything else is tribal politics. Two big Sunni tribes, the Shammar and the Dulaim, stretch from northern Saudi Arabia through western Iraq and Jordan and up into eastern Syria. Some observers say these tribes have sworn a blood oath against Assad. If so, a decisive phase of the Syrian war may have begun. 

By David Ignatius

David Ignatius’ email address is davidignatius@washpost.com. ― Ed.

(Washington Post Writers Group)