On September 30, Russia broke from existing frameworks when it began its own airstrikes against rebels in Syria. As the airstrikes continued, it became clear that Vladimir Putin’s sympathies toward the brutal Assad regime were become manifest in the bombs Russian aircraft dropped not on Assad’s strongholds, but on anti-regime rebels backed by the United States and other western coalition forces.

Now both Syrian activists and Iranian officials are reporting that over the past few days, Iran has sent over 1,500 fighters into Syria via Damascus; Hezbollah fighters have also made the journey. Officials claim that these fighters are prepping to launch an assault on militants in Aleppo in northern Syria, and that this move has been bolstered by Russian airstrikes.

Via Fox News:

“Sending more troops from Hezbollah, and Iran only increases the shelf life of the Syrian regime, which is destined to end,” Maj. Jamil Saleh, the leader of Tajammu Alezzah, a CIA-backed Free Syrian Army faction, told the AP. “It will only add more destruction and displacement.”

Their arrival is almost certain to fuel a civil war in Syria which has already claimed the lives of more than 250,000 people and displaced half of the country’s population.

Iranian and Syrian officials have long claimed Iran has advisers and military experts in Syria. But Wednesday’s reports are the first confirmation of Iranian fighters actually taking part in combat operations there.

Before Wednesday, we knew that Iran was at least sending advisors into the region to help pro-Assad fighters. On Friday, Iranian officials confirmed that Brig. Gen. Hossein Hamedani was killed during an airstrike on the outskirts of the northern Syrian city of Aleppo. He was on an advisory mission to Syria, and is believed to have been instrumental in the training and organization of Assad’s anti-rebel forces.

Now, we know this was all part of a bigger plan—Hamedani isn’t the only high-profile Iranian official that has been killed in connection with the current Syrian civil war.

Aleppo is strategically important. After officials at the Pentagon dumped their “train and equip” program for rebel forces, Ash Carter told the press that the work that US forces have done with rebels in northern Syria is a prime example of what they would like to pursue with other groups in other parts of Syria going forward. Aleppo was our “success story” in terms of the anti-ISIS mission—and that’s where an Iranian general was holed up, organizing an assault on western-backed forces.

ISIS attack threats doubled in 2015. We should be focused on “degrading and destroying” extremist efforts in the Middle East and around the world, but instead we’re forced to tiptoe around and negotiate with two of the most hostile regimes on the planet—one of whom we just agreed to trust with a budding nuclear program.

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