As the United States prepares to provide weapons to Syrian rebels, it will rely on Turkey and Jordan to move arms into the country. Jordan will doubtlessly aid the United States, but its willingness to fully support Assad’s ouster remains far from evident. Despite the show of force touted in June’s Eager Lion military exercises, as well as recent stationing of US fighter jets and missiles in Jordan, closures along the Jordanian-Syrian border point to a distrust of the rebels.

In response to Free Syrian Army (FSA) victories in southwestern Syria, Jordan closed for the first time its main border crossing. On March 25, the FSA announced its seizure of a nineteen-mile stretch of the Jordanian-Syrian border, running from southwest Daraa to the Golan Heights. Hours later, Jordan closed the Nasib/Jaber border crossing, citing security concerns stemming from the overthrow of Assad’s divisions by rebel militias. The move indicated a preference for Assad’s command and suggested skepticism of the FSA. The closure of the Jaber crossing, which has yet to be re-opened, marked the first of many and preceded a redoubled effort to secure the border. Soon after, Jordan doubled the number of soldiers along its border and a few months later, retained 700 US soldiers, patriot missile battries, and F-16 fighter jets after the conclusion of the Eager Lion military exercises. While some have conjectured that US military resources in Jordan will eventually catalyze a no-fly zone, Jordan will not cooperate in such an operation absent an international mandate.

Throughout May, ferocious clashes in the Daraa proctorate led Jordan to close forty-five of its border crossings.As fighting intensified in the South, geographic boundaries became increasingly meaningless and prompted Jordan to drastically curtail its refugee intake. Errant rockets befell Jordanian border towns throughout the month, scorching farmland and damaging houses. Jordanian communities even imposed nightly electricity blackouts to reduce the likelihood of Syrian rebels mistaking their homes for army barracks. This fighting occurred against the backdrop of a sweeping government counteroffensive to retake the South.The campaign is reaching its denouement, with Hezbollah and Iranian fighters now encircling the city of Daraa, which lies less than a mile from Jordan. The upswing in violence across the border has been attracting hundreds of Jordanian salafists, whom the government denies passage.

Jordan’s tightened border security stems from two concerns: the movement of salafi jihadists to and from Syria and the multiplication of its refugee population. There are reportedly 5,000 jihadists in Jordan lying in wait to join the fight, not to mention at least five hundred Jordanian salafists already fighting in Syria alongside groups such as Jabhat al-Nusra. If Jordan fails to contain those yearning to rush into the fray, it risks the eventual return of thousands of radicalized fighters.Worse yet, if the powerful jihadist factions in the opposition gain control ofsouthern Syria in a post-Assad scenario, the Jordanian islamist movement may feel empowered and inspired to topple the pro-West Hashemite monarchy. An early sign of violent spillover occurred last October, when Jordanian authorities thwarted eleven Jordanian salafists plotting to attack shopping malls and Western diplomatic missions in the county.

Jordan’s caution in embracing the opposition mirrors the reservations held by the United States. Already the country has worked with the United States to maximize influence with moderate elements of the opposition. Starting late last year, Jordan hosted US special operations teams who were training selected groups of rebels to use anti-tank and anti-aircraft weaponry. Jordan will gradually taper its support of the opposition so long as it remains fractured and embedded with Islamic militants.Unlike the United States, however, Jordan will bear the potential repercussions of arming rebels much more directly. The high possibility that weapons will disperse among the opposition would hasten jihadist groups’ accession to power. Furthermore, giving generous lethal aid to the opposition might anger an Assad whose loss of power is far from inevitable. Jordan’s lack of trust in the opposition coupled with the tenacity of Assad’s regime forces it to play an ambivalent and flexible foreign policy.

On May 7, King Abdullah II welcomed Iranian Foreign Minister Ali Akbar Salehi. The visit ended in a joint press conference in which Salehi affirmed that both Iran and Jordan strongly support dialogue between the Syrian government and the opposition and that Jabhat al-Nusra should be excluded from talks. Amman’s public cooperation with Iran illustrated its desire to serve as a mediator rather than provoacateur. Whether Jordan reopens its borders to a renewed rebel offensive on the South, enabling weapons and fighters to flow unhindered across its border, will determine its role in the conflict. Although given its misgivings over the opposition and goals of diplomatic neutrality, this appears unlikely.

Henry Johnson writes on US foreign affairs.