Extremist militants affiliated with the Islamic State in Iraq and Sham (ISIS), the successor organization to Al-Qaeda in Iraq, have scored a series of spectacular victories in recent days. On Monday, ISIS overran Iraq's oil-rich second city of Mosul to seize control of vast weapons stores, and armored Humvees supplied by the US. ISIS has also seized about $429 million in cash from Mosul's central bank and kidnapped dozens of Turkish consular officials. Now, the group has the Iraqi capital Baghdad in its sights, and numerous military experts believe the city is vulnerable.
How did we get here? The fall of Mosul and subsequent advances by ISIS could not have happened without the growing strength of ISIS in Syria. Local officials in Mosul report that many ISIS fighters entered Mosul from the adjacent Syrian province of Deir Ezzor. A Stratfor analysis released in the wake of the offensive observes that "The most notable element of these attacks was the use of technicals in rapid raids -- similar to tactics used in Syria, but much less common in Iraq." This implies that ISIS applied techniques it learned in Syria to successfully execute the attacks.
Furthermore, ISIS had been steadily advancing toward the Iraqi border from Deir Ezzor for a month before this week's attacks. On May 14th, rebel Deir Ezzor Military Council head Muhannad Al-Tallaa estimated that his position relative to ISIS was "poor" and would worsen "because we are running out of ammunition and ISIS have superior military equipment.” Five days before the Mosul offensive, the opposition Syrian Observatory for Human Rights indicated that ISIS had been making consistent gains in northern Deir Ezzor, and had acquired control of territory on the Iraqi border. Clearly, ISIS has been able to quickly exploit its new territorial holdings in Deir Ezzor to dramatic effect.
It did not need to happen this way. On January 3rd, 2014, large protests against ISIS abuses erupted across opposition-held areas of Syria. That same day, a new coalition of moderate rebel brigades was formed explicitly to fight ISIS. Within a week, activists were reporting that rebels had expelled ISIS from most of northwestern Syria, where ISIS has yet to recover its former influence six months later. The opposition also managed to fully expel ISIS from Deir Ezzor as a result of this offensive.
In fact, three days into the Syrian rebel offensive, ISIS looked poised to suffer a very severe blow. At the start of the offensive, the main ISIS headquarters across Iraq and Syria was located in the north-central Syrian city of Raqqah. Rebel fighters acquired territory in Raqqah City itself on January 6th, and were advancing toward these headquarters. However, ISIS launched a fierce counterattack one week later to fend the rebels off.
Syria's rebels paid a steep price for their offensive. In the northwestern province of Aleppo, a rebel stronghold for nearly two years, Assad regime forces made significant inroads during January 2014. They cut a crucial rebel supply line in the province and recaptured their first piece of territory in Aleppo City proper. They also launched an intensive "barrel bomb" campaign on Aleppo City that turned many neighborhoods into ghost towns.
The three weeks from January 22nd-February 14th were the bloodiest of the Syria conflict due largely to intensified regime airstrikes with barrel bombs, or shrapnel-filled explosive barrels. Yet during those three weeks, the eyes of the international community were on Geneva, where diplomatic talks on Syria were sputtering toward failure. Syrians under bombardment took to calling barrel bombs "Geneva barrels" in mockery of the negotiations. U.N. envoy Lakhdar Brahimi, who convened the talks, has since resigned and blames the Assad regime for their collapse.
Saudi Arabia moved to provide Syrian rebels with anti-aircraft weapons in the aftermath of the Geneva talks. However, this weapons transfer was vetoed by the Obama Administration, which has repeatedly warned that such steps could cause "weapons to fall into the wrong hands". With no way to stop the barrel bombs, Syrian rebels in Aleppo grew weaker and were unable to pressure ISIS.
ISIS has since stabilized its western front in Aleppo, turning east toward Deir Ezzor and the Iraqi border. On May 21st, a Syrian rebel spokesman in Deir Ezzor estimated that ISIS had transferred roughly 3,000 fighters into the province since February. For a militant organization estimated to have roughly 10,000 fighters under its command, this represented a very substantial redeployment. The redeployment eastward undoubtedly improved ISIS fortunes in both Deir Ezzor and in Mosul.
As ISIS fighters parade toward Baghdad in American-made armored Humvees, it is safe to say that weapons are in the wrong hands. Yet ongoing events in Iraq would likely not be happening had the U.S. heeded earlier requests by Syrian rebels for better weapons. Since weapons are already in the wrong hands, the U.S. should at least act to ensure they are in the right hands.
Syrian rebel forces have proven themselves as a fighting force willing and able to take on ISIS. Even though they are dramatically outgunned, Syrian rebels have never disintegrated as Iraqi forces did this week. Even though they also battle the Assad regime, Syrian rebels have a better record against ISIS than Iraqi forces over the past six months. To stop ISIS today, we must pressure it at both of its front lines -- in Baghdad, and in Aleppo. To help stop ISIS advances south toward Baghdad, Syrian rebels should receive the tools they need to resume attacks on ISIS's northwestern front.
Ghanem is the senior political adviser and government relations director for the Syrian American Council in Washington, a board member of the Coalition for a Democratic Syria and a fellow at the Syrian Center for Political and Strategic Studies.