This is a guest post from Idean Salehyan, Associate Professor of Political Science at the University of North Texas and the author of Rebels Without Borders: Transnational Insurgencies in World Politics (Cornell Univ. Press, 2009).

Reports have emerged that Turkey is supporting a group of military defectors from Syria, which have organized under the name, the ‘Free Syrian Army’ or FSA. Led by Riyad al-Asad, a former Colonel in Bashar Assad’s army, this group claims to have inflicted a series of impressive attacks against regime forces. Although the extent of Turkish involvement is still unclear, providing sanctuary to the FSA is seen by many as an attractive way to tighten the screws on an increasingly brutal and unpopular regime.

Indeed, in a recent editorial the Wall Street Journal (“Turkey Turns on Assad, ” October 31), makes a strong case for supporting the FSA. It argues that the United States should begin by giving the FSA “diplomatic and non-military support,” but that “arms shouldn’t be ruled out”. In the coming weeks and months, such voices are likely to become more numerous as the international community seeks a solution to the current impasse.

Diplomatic pressure and sanctions on Damascus do not appear to be working, as Assad’s ruthless suppression of peaceful demonstrators continues. However, supporting an armed opposition group would open a new—and potentially disastrous—phase in the uprising. The United States and Turkey must carefully consider what such a step may mean for the Syrian opposition and for the region as a whole. This would not be the first time the US has supported cross-border militant groups—the Nicaraguan Contras operated from bases in Honduras and the Afghan Mujahedin operated from inside Pakistan. Current research on transnational rebel organizations and externally-sponsored militant groups suggests that Turkey may be in for a long insurgency and a regional war.

First, foreign-backed opposition groups can quickly lose legitimacy at home. Assad would love to portray the Syrian opposition as agents of a foreign power. As disingenuous as this tactic may be, a sense of external threat is likely to cause those on the fence to rally behind the leader to confront a common enemy. Attacks on peaceful, unarmed protestors have eroded Assad’s popularity at home and abroad; confronted with this brutality, regime supporters must stop to question their own loyalties. An armed, US/Turkey-backed militant group is much easier to portray as illegitimate, power-hungry, and part of a Western conspiracy. One reason for the success in Libya is that the US steered clear of the Transitional National Council until relatively late in the rebellion. Hastily recognizing the opposition could cause it to lose credibility in the eyes of many Syrians

Second, as unpopular as the Syrian regime is, the strategic decision to relocate to Turkey reveals the Free Syrian Army’s relative weakness. Rebels in Libya were able to secure domestic strongholds in the east early on, while they advanced toward the capital city-by-city. By contrast, Syrian dissidents have been unable to find a permanent, domestic base of operations free from government control. With an external sanctuary the FSA is much less likely to be defeated militarily, but this does not necessarily mean a swift rebel victory. Instead, cross-border groups often fight bloody, protracted insurgencies which end in a stalemate. The Afghan/Pakistan conflict nexus offers just one such example.

Third, foreign backing of rebel organizations is an indirect means of prosecuting an international war. These indirect means tend to escalate to more direct confrontations. If Turkey backs the FSA, Syria is likely to retaliate by opening up its territory to Turkey’s Kurdish rebels as it had in the past. Turkey has it bad enough with the Kurdish Worker’s Party (the PKK) ensconced in Northern Iraq; it has not been able to defeat the group despite decades of trying. Cross-border attacks and raids by proxy forces, along with mutual recriminations, often escalate to more severe international conflagrations.

Wanting to ‘do something’ is understandable. But the track-record of funding rebel groups and transnational dissidents is cause for caution. It will take much more than funneling arms and money to a relatively obscure rebel group to oust Assad from power. The first principle in dealing with Syria should be to ‘do no harm.’ Arming the opposition does not appear to satisfy that criterion.

As the Syrian regime fails to bend under international pressure, debates about the appropriate next-step will continue. All options should be on the table in dealing with Assad’s brutality. If attacks on civilians intensify, the international community has a responsibility to protect innocent civilians with all appropriate means, including armed intervention as a last resort. However, before agreeing to back armed militants, all stakeholders should stop to carefully consider the likelihood of success versus yet another front in the Middle East quagmire.