On Tuesday evening, in an address marking the one-year anniversary since Lebanon has been without a president, Prime Minister Tammam Salam made a perceptive comment.

He warned that the absence of a president had caused damage to the country’s formula of sectarian coexistence, and perhaps even threatened Lebanon’s very existence.

Salam may have missed the point that those blocking an election, or perpetuating that blockage, are uninterested in preserving the system as it is. While Michel Aoun is the official culprit by refusing to authorize his parliamentarians to go to Parliament and elect someone other than him as president, Hezbollah has supported him. It has done so very likely because it wants to see Taif collapse to ensure that Shiites will gain more political power.

With Bashar Assad’s regime looking more vulnerable by the day, Hezbollah’s need to protect its political stakes in Lebanon are rising. For this to happen the party needs to change Taif in such a way as to allow Shiites, and with them Hezbollah, to control a larger share of power in Lebanon’s parliament and government. For many, Hezbollah’s unwillingness to help break the deadlock over the presidency is really aimed at eroding Taif.

Such behavior is driven by a logic of power and sectarian one-upmanship very different from the notions of confessional coexistence and compromise at the heart of Lebanon’s National Pact. Any effort to overhaul the political system to reshape the confessional equilibrium in the interests of one particular sect challenges the principles upon which Lebanon was built.

Lebanon embodies what the author Philip Mansel has called “Levantinism.” He wrote a very uneven book on the subject in 2010, but his introduction provided a valuable rundown of the characteristics of historical Levantine cities (and by extension Levantine countries), particularly the three on which he focused: Smyrna, Alexandria and Beirut.

To Mansel, Levantine cities are cities that developed in the eastern Mediterranean on the borderline between the Ottoman Empire and Europe, between East and West. Because such cities were characterized by a mixing of cultures and religions, their essence was cosmopolitanism and flexibility. “They could be escapes from the prisons of nationality and religion. In those cities between worlds, people switched identities as easily as they switched languages,” Mansel wrote. The Levant “put deals before ideals” and stood “for a world of ‘shifts and compromises.’”

These qualities, for qualities they are, were largely abandoned in Smyrna and Alexandria, as both succumbed to the pull of intolerant forms of sectarianism and nationalism. Beirut, despite a 15-year conflict in which the durability of sectarian coexistence was repeatedly put in doubt, nevertheless emerged with it power-sharing system still standing. Lebanon’s war ended with a new sectarian compromise formula, represented by Taif, and, despite the displeasure of some, it has survived. But until when?

Perhaps the better question is why do some societies readily give up on coexistence in favor of ideals of homogeneity that are so much less enriching and interesting? Diversity brings prosperity and the delights of variability. What is particularly desirable in living perpetually with one’s own; with those who think, act, eat and play like us? Familiarity is doubtless less threatening, but it is also devoid of challenges, of anything that is enthralling.

While much of the globe has embraced cultural diversity, the Arab world is a pioneer in the opposite direction. The post-World War IMiddle East is being broken apart by societies aspiring to sectarian or ethno-sectarian ministates that stifle all dissimilarity. When, or if, such states are formed and the region is crisscrossed by such dreary entities, then what? Will their ambition be to live in autarky? Surely not. They will be obliged to cooperate with their neighbors, engage in trade, promote cultural interchange, all those things that societies require to develop.

In other words these ministates will readily recognize the benefits of interaction with states or societies different than theirs. Why, then, is such diversity acceptable, even desirable, when it occurs outside national borders, but not inside those borders? There are simply no convincing answers.

Which brings us back to Hezbollah and the potential threat it poses to the Taif system. The party is not seeking to create a Shiite ministate in Lebanon, so, publicly, it has not given up on coexistence. But what it is doing may be more pernicious. If it seeks to enhance Shiite power (and defend the interests of its regional sponsor, Iran) Hezbollah risks sawing off the branch of coexistence on which all Lebanese religious communities sit.

Once sectarian balance is fiddled with, everyone will want in on the game. Maronites, Sunnis and Druze will also insist that amendments be introduced to the power-sharing system in ways that give them a greater slice of the pie. Such disputes will never bring about a new equilibrium, since no equilibrium exists that can satisfy the contending appetites of all the sects, but they may well destroy the foundations of our political system.

There is some resilience left in Lebanese confessional coexistence. One reason the country has been able to avoid the sectarian problems of other Arab states in the past four years is that long ago it recognized the reality of sectarian divisions and built a system to address it. The reflexes of compromise are ingrained in us, regardless of the polarization all around us.

Will this spare Lebanon the worst? No one can say. But one thing we must worry about are those parties or sects who, in trying to strengthen themselves unilaterally, bring the edifice of coexistence down on the heads of all Lebanese. Salam is right to be concerned.