What happens when you couple a Mexican standoff with a game of Russian roulette? You get Lebanese politics over the last several weeks: The revolvers are out, the politicians keep pulling at the trigger, and luckily, so far, no bullets have been chambered.

There are two groups in this standoff. They are polarizing Lebanese society based on sectarian identity and accusing one another of serving foreign interests. On the one hand, there is the opposition that consists of a near-monolith Shiite community led by Hezbollah, allied to half the Maronites under General Michel Aoun and a smattering of Sunnis, Druze, and Greek Orthodox. This group is accused of being agents of Syria and Iran. On the other hand, there is the March 14 coalition, named after the date of mass protests in 2005 that precipitated Syria’s withdrawal from Lebanon. It consists of a near-monolith Sunni community led by the Hariri family, the other half of the Maronites, the vast majority of the Druze and Greek Orthodox, and Lebanon’s few liberal democrats. This group is accused of being lackeys for America and Saudi Arabia. More or less, the country is torn in half between the two groups.

For the past three weeks, the opposition has been besieging the Cabinet led by the March 14 coalition. Each is angling for total victory. For the opposition that would mean controlling the parliament through new elections, holding veto power over Cabinet decisions, choosing the next president of the country, and safeguarding the Syrian regime. For the March 14 coalition, total victory translates into controlling the Cabinet and the presidency, disarming Hezbollah, and setting off a cascade of events that eventually leads to the overthrow of the Assad dynasty in Syria.

Lebanon functions according to an unwritten sectarian formula, whereby the three main component groups of the country — Sunnis, Shiites, and Maronites — need to be content with their share of the pie in order for civil peace to prevail. Total victory for the opposition would mean eviscerating the Sunnis and half the Maronites, while total victory for the March 14 group would demean the Shiites and the other half of the Maronites — hardly a recipe for peace.

How did Lebanon get to this point where one false move, say a Sunni suicide bomber detonating himself among Shiite crowds, could trigger a return to civil war? The answer can be traced to a tight-lipped Belgian man called Serge Brammertz. He was appointed by the United Nations as the lead investigator into the assassination of the former prime minister, Rafik Hariri, who was killed in a car bombing almost two years ago. Mr. Brammertz has been handing in straightforward progress reports that haven’t indicated any suspects. His latest, released last week, finally settled the matter of who perpetrated the crime: a suicide bomber who likely knew that the target was Hariri and who most probably detonated the bomb himself. Although he is carefully piecing together DNA and other evidence, Mr. Brammertz has still not named this suicide bomber. But the implication is that the bomber was a jihadist.

In six months, Mr. Brammertz is supposed to hand in his final report. This time it won’t be a sterile progress report but rather an indictment. The indictment will mark who wins and loses in the game of Lebanese politics — the opposition or March 14. The rosiest scenario for the opposition is that Mr. Brammertz points a finger at a shadowy Sunni jihadist organization that may or may not have had a state sponsor like Syria. In this scenario, Mr. Brammertz would find it hard to pin the shadowy mechanisms of manipulating these jihadists on the Syrian regime. The best-case scenario for March 14 would be a direct indictment of the top Syrian leadership resulting in international sanctions and accelerated efforts to spark an uprising against the Alawite minority now in power in Damascus.

A meddlesome Syria is a geographical and historical fact of life for Lebanon. If Syria is off the hook, then the internal political scales in Lebanon would tip in favor of the opposition, while if the Syrian regime is cornered, then March 14 can force its rivals to concede political ground.

Both the opposition and March 14 are assuming that, in lieu of a smoking gun, Mr. Brammetz would only be able to present circumstantial evidence showing that the Syrians meant Hariri and other recent victims of assassinations harm. The international tribunal that would be set up to judge such circumstantial evidence would need to decide whether there was Syrian culpability and if so, how far up the chain of command it reached. Such a decision will be limited or augmented by the legal charter setting the scope of the international tribunal. The opposition and March 14 are now bickering over who gets to author this charter, in other words, who gets to decide whether the tribunal will have any teeth or not.

The standoff can end either in a political settlement or violence. A political settlement is the most likely temporary palliative that the feuding parties will opt for in order to avoid violence. The opposition wants to weaken the charter of the tribunal. First they want an independent body of six experts to review it, probably rendering it innocuous. Then they want veto power in the Cabinet that would decide on it. And then they want the charter to go to the president, who is allied with the opposition, before it goes to the parliament, controlled by March 14. If these demands are not met, then the opposition will allow the standoff to continue while demanding a new electoral law and early elections that they believe will give them a majority in parliament. A political settlement would not give the opposition total victory, but it would reset the situation in its favor.

The March 14 coalition is hoping to hold on to its gains — controlling the parliament, the Cabinet, and a finished charter that has already been voted on by the Cabinet and sent to the United Nations — and it hopes to do so with international support and cover. Yet this position may fall apart if a country like Russia uses its Security Council prerogatives to stall formation of the international tribunal until the standoff in Lebanon is resolved, or until the Syrians, who are chummy with President Putin, give the thumbs up.

I would like to see Hezbollah disarmed, and I would like the Syrian people to live under a democratically elected government — goals shared with the March 14 coalition. But I ask myself, at what price in Lebanese blood is this feasible? The Syrian regime and Hezbollah manipulated sectarian tensions and local Lebanese politics and have maneuvered the opposition well, and they stand to fare better with a political settlement than the March 14 coalition. The Americans are telling the latter to hang in there and keep up its defiance, but America doesn’t have a coherent policy to go after Hezbollah or to overthrow the Syrian regime.

A false move in Beirut may result in a bloodbath. Who will take responsibility for that? Someone needs to counsel March 14 to stand down for the time being, or at least until Washington gets its muddled policy sorted out.

Mr. Kazimi can be reached at nibraska@yahoo.com.