The alliance between Russia and the regime of Bashar al-Assad goes back decades. Here's a bit of historical context that explains why Russia is fighting to prop up its closest ally in the Middle East. (Ishaan Tharoor and Jason Aldag/The Washington Post)

The head of al-Qaeda’s offshoot in Syria has called on followers to carry out retaliatory attacks in Russia, raising the specter of blowback on Russian soil over Moscow’s military intervention to aid Syria’s embattled government.

Just hours after the call from Abu Mohammed al-Jolani, the leader of Jabhat al-Nusra, two mortar shells landed in the perimeter of the Russian Embassy in the Syrian capital, Damascus. No casualties were reported.

Meanwhile, Abu Mohammed al-Adnani, a spokesman for the Islamic State militant group, issued a statement criticizing the United States. He described President Obama as a “dumb mule” and an “idiot” who has extended the war “as we wanted” by not taking more robust action in Syria.

Russia has used cruise missiles and fighter jets to strike targets in Syria held by Islamic State militants and other factions battling Syrian President Bashar al-Assad, including Jabhat al-Nusra, also known as the al-Nusra Front.

President Vladimir Putin has argued that containing the extremists is a national security concern for Russia, with its restive North Caucasus region serving as a breeding ground for militants. But Russia also has strategic interests in supporting longtime ally Assad, including gaining footholds in the Middle East and the Mediterranean region.

“The new Russian invasion is the last arrow in the quiver of the enemies of the Muslims,” Jolani said in an audio recording released late Monday. He urged those in the Caucasus region to “distract” Moscow from the conflict in Syria, calling for attacks on both civilian and military targets in Russia.

“If the Russian soldier kills from the masses of [Syria], kill from their masses,” he said in the 21-minute speech. “And if they kill from our soldiers, kill from theirs. One for one.”

Jolani set a bounty of 3 million euros ($3.4 million) for the killing of Assad and 2 million euros ($2.3 million) for the elimination of Hasan Nasrallah, the leader of the Lebanese militant group Hezbollah, which is backing the Syrian government on the battlefield.

In his audio recording released Tuesday, Adnani said the Islamic State has benefited from U.S. inaction.

“The idiot should have made haste and not wasted time by trying solutions,” he said of Obama, according to a translation from the SITE Intelligence Group. He added that America would “come via land soon” and meet “your destruction and ruin and end.”

Adnani also eulogized Fadhil Ahmad al-Hayali, the No. 2 Islamic State leader who was killed in an airstrike by a U.S.-led coalition in Iraq in August. The coalition has been attacking the Islamic State in Iraq and Syria for months.

“We consider that he did not die, for he has raised men and left behind heroes,” Adnani said.

The United States and Russia have publicly traded barbs about the effectiveness of each other’s air campaign since Moscow stepped up military action.

Russia has said that its airstrikes are directed against the Islamic State, but U.S. officials have contended that Moscow has largely targeted other groups, including U.S.-backed rebel forces.

Putin said Tuesday that Moscow has asked the United States to provide examples of targets that it considers legitimate but has received no response. Washington also did not respond to a request to provide information on sites that it did not wish to be targeted, he said.

“It seems to me that some of our partners are just messed up in the head,” Putin said.

The Syrian army, backed by Russian airstrikes and supported by Hezbollah and Iranian fighters, has made progress against rebel groups in recent days. But Islamic State militants also appear to have benefited from Russian strikes against those groups, advancing on the outskirts of Aleppo, Syria’s largest city.

Despite their gains, pro-
government forces also have suffered losses; two Hezbollah figures and a top Iranian commander have been killed on the battlefield in recent days. The resistance put up by U.S.-backed rebels can be partly attributed to U.S.-supplied antitank weaponry.

The United Nations’ special envoy to Syria, Staffan de Mistura, was in Moscow on Tuesday to urge Russia to help bring about a political resolution in Syria.

Russian Foreign Minister Sergei Lavrov said that Russia’s military campaign was not hampering the political process and that a “swift launch” of steps toward a political resolution is consistent with Russia’s goal of uniting “all healthy forces” to save Syria.

Abbakumova reported from Moscow.

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