As the United States becomes more involved in the war in Syria, it’s important to consider the role played by non-state actors—particularly the Shia militant group Hezbollah. Understanding the role of such entities shows how proxy fights are inherently dynamic and unpredictable. Hezbollah may perceive it has the upper hand today, but should Assad fall, it’s putting itself in a risky position.

So why, then, are Hezbollah fighters risking their lives in Syria in the first place? And why is the organization risking its political standing, in Lebanon and internationally, to defend Bashar al-Assad’s regime? Conventional thinking about Hezbollah’s relationship with Syria and Iran takes Hezbollah’s loyalty to Assad for granted. After all, Hezbollah receives a staggering amount of arms and resources from Iran, the bulk of which flow through Syria to reach Hezbollah’s coffers. Hezbollah rightly perceives that its military victories to date were made possible by Tehran’s generosity and its willingness to replenish weapons and materiel lost in various encounters with Israel. It is unlikely that a post-Assad Syrian regime would be willing to continue to serve as a conduit for Iran.

Furthermore, the increasingly sectarian nature of the civil war in Syria—which pits Sunnis against Shia, Alawites, Christians and Druze (while the Kurds strive to carve out an autonomous space)—has strengthened Hezbollah’s commitment to defend its perception of Shiite interests in the Levant. Nevertheless, at the grand-strategic level, Hezbollah’s decision to devote increasingly greater and more public resources to upholding Assad’s control of Syria might prove to be an enormous blunder for the organization.

Hezbollah’s behavior is puzzling in three related respects. First, recent events have called into question Iran’s reliability as an ally. Western sanctions have dealt a considerable blow to the Iranian economy, decreasing the amount of aid Iran can funnel to Hezbollah. Additionally, the development of Iran’s nuclear program might make Hezbollah less important as a deterrent force for the Iranian regime. Second, Hezbollah’s protracted and effective resistance against Israel has translated into concrete political gains. In the most recent election, Hezbollah secured twelve seats in the Lebanese parliament and two cabinet ministries. Hezbollah enjoys considerable loyalty from the Shia community in southern Lebanon, where the group essentially acts as a ministate, as well as credibility in the Middle East and globally from its anti-Western resistance. Third, Hezbollah’s actions in Syria are undermining the very thing that would allow it to be more independent from Iran: local political legitimacy. Drawing even closer to Assad and Tehran could isolate Hezbollah domestically. Even Lebanese president Michel Suleiman—a Hezbollah ally—publicly chastised the group for prioritizing Syria over Lebanon. While local political support cannot substitute for the arms and resources provided by Iran, if Hezbollah’s strategic objective is to secure real political power in Lebanon it cannot afford to alienate the Lebanese public.

While Hezbollah leader Hassan Nasrallah now publicly acknowledges the group’s presence in Syria, Hezbollah’s involvement in the war began as a covert affair. Hezbollah-run funerals for the “martyrs” who died in Syria did not disclose where the fighters lost their lives. Nasrallah’s initial hesitance to admit to the group’s involvement in Syria suggests he is aware of the political costs of siding with a dictator’s ruthless suppression of his own people, especially in the broader context of the Arab Spring. Hezbollah stood by the Iranian regime in 2009, but the violence there, though brutal, pales in comparison to the ongoing carnage in Syria. Additionally, Nasrallah likely wanted to avoid giving Israel a pretext for intervening in the conflict.

Given these costs, why would Hezbollah go public? Most likely, Hezbollah was drawn into incrementally greater involvement in the Syrian conflict to the point that its role could no longer be plausibly denied. The more Assad’s forces were in need of Hezbollah’s assistance—through training and provision of fighters—the more Hezbollah had to ratchet up its commitment to the conflict.

This kind of mission creep is prevalent in the context of proxy warfare. Relations between states and their proxies often operate as “open secrets,” where third parties are aware of the alliance but not its specific provisions. The ambiguity and clandestine nature of these relationships creates opportunities for allies to exploit and draw one another into costly foreign-policy gambits.

Furthermore, the deep institutional and interpersonal ties between proxies and their state sponsors cultivate alliance commitments independent of foreign-policy interests. Iran essentially created Hezbollah out of Amal, Lebanon’s Shiite political movement, in 1982. Since then, it has devoted considerable resources to shaping the organizational structure and ideological preferences of the group—Hezbollah cadres continue to pledge an oath of fealty to Iran’s Supreme Leader, Ali Khamenei. And over the years, Hezbollah has served as a loyal proxy of Iranian strategic interests around the world. In fact, rather than drift apart over time, Hezbollah has recently become even more enmeshed with the Iranian regime, especially following the 2008 assassination of Imad Mughniyah, a senior Hezbollah commander who sought to pull Hezbollah away from Iran’s orbit, and his replacement by Mustafa Badreddine.

It is notable that Hamas, which also receives substantial support from Iran, disavowed Assad in early 2012. While sectarian considerations certainly played a part in that decision—Hamas members are Sunni, while Hezbollah are Shia—Hamas also lacks a comparably long and inextricable relationship with Iran.

Even if Assad is still ruling Syria a year from now, Hezbollah might pay for its loyalty. Sectarian tensions are on the rise in Lebanon, spillover effects from Syria. Though Hezbollah still retains the allegiance of much of the Shia population in Lebanon, its overall political position in the country could be greatly damaged by its current role in Syria. Hezbollah soon could find itself on defensive politically—and even militarily—in Lebanon. Furthermore, if Assad remains the leader of a rump Alawite state, he might have very little to offer Hezbollah if he fails to secure crucial cities such as Homs, which serve as conduits for Iranian supplies to Hezbollah. And, it goes without saying that Hezbollah would find itself in an incredibly hostile world if the Assad regime falls. In the latter two cases, Hezbollah would have spent blood and treasure for little return.

Erica D. Borghard is a Ph.D. candidate in political science at Columbia University. Her dissertation concerns proxy warfare and the conditions under which allies are drawn into foreign policy misadventures.

Image: Flickr/Ben Hammersley. CC BY 2.0.