Russian military aircraft on Tuesday and Wednesday targeted rebel positions in Aleppo and elsewhere in Syria. Not much new in that—except the Kremlin made a point of announcing that the bombers are flying out of an air base in western Iran.

The bombing runs are another sign that Moscow and Tehran are consolidating their strategic ties in the wake of President Obama’s nuclear deal with Iran. It follows the Kremlin’s decision last year to sell the S-300 system to the mullahs despite earlier promises to withhold the surface-to-air missiles. As retired Russian Gen. Evgeny Buzhinskiy told us in a phone interview Tuesday, “I think cooperation between Iran and Russia is growing, and military cooperation is at the top.”

The immediate motive for the latest Russian-Iranian strikes in Syria is payback for recent opposition gains in Aleppo. Russian President Vladimir Putin and Syrian dictator Bashar Assad have laid siege for weeks to some 300,000 people remaining in eastern Aleppo, cutting off supply routes to the rebel-held area while the Russians pummeled civilians from the air.

The Western response has been to plead with the Kremlin for longer cease fires to allow the passage of food and medicine. But earlier this month the Army of Conquest coalition, which includes al Qaeda’s Syrian affiliate and which fights alongside more moderate and secular forces, pushed through the Syrian-Russian blockade, re-opening supply routes to trapped civilians.

The opposition gains are a reminder of the weaknesses of Assad’s army, a demoralized force with as few as 20,000 battle-ready troops. They have been unable to retake Aleppo despite Mr. Putin’s air cover and ground support from Iran and its Shiite proxy Hezbollah.

Assad vows to take every inch of Syria, and the opposition is committed to the same goal. Barring a tilt in the balance of forces, such as a Western no-fly zone that grounds Assad’s pilots, the bloody stalemate will continue. So too will the Syrian civil war—and with it the radiating instability, refugee flows and power vacuums filled by jihadists.

This may suit the interests of Russian and Iranian interlopers, who will shed few tears over the human suffering in Aleppo as they expand their influence in the Levant. How it benefits U.S. interests, or furthers Western values, is a question the next American President will have to consider.

Source : wsj.com