BEIRUT — Iran allowed Russian warplanes to take off from its territory to bomb targets in Syria on Tuesday, an unprecedented move that underscores the deepening cooperation between two powerhouses heavily invested in the Syrian civil war.
The Iranian deployment increases Russia's foothold in the Middle East and widens Moscow's bombing campaign in Syria, bolstering President Bashar Assad's government ahead of a new round of peace talks the United Nations hopes to convene in coming weeks.
The long-range bombers took off early Tuesday near the Iranian city of Hamedan, 280 kilometers (175 miles) southwest of the Iranian capital, and struck targets in three provinces in northern and eastern Syria, the Russian Defense Ministry said.
The Russian warplanes then returned to Russia and no Russian forces remained stationed in Iran, said a U.S. official, speaking on condition of anonymity because the official was not authorized to speak to reporters about the matter.
"Russia's use of an Iranian base represents a turning point in Russia's relations in the Middle East. ... It sends a powerful message to the United States and regional powers that Russia is here to stay," said Fawaz Gerges, professor of international relations at the London School of Economics.
Russia had talked about the possibility of flying planes out of Iran since late last year, but its decision to do so on Tuesday came as a surprise, U.S. officials said.
Col. Christopher Garver, a U.S. military spokesman in Baghdad, told reporters at the Pentagon on Tuesday that the Russians activated a communications link with coalition officials just ahead of the bomber mission.
"The Russians did notify the coalition," he said, adding that they "informed us they were coming through" airspace that could potentially put them in proximity to U.S. and coalition aircraft in Iraq or Syria.
Asked how much advance notice the Russians gave the U.S., Garver said, "We did know in time" to maintain safety of flight.
U.S. officials said the setup at the Iranian air base occurred very quickly, perhaps overnight. One military official said the Russians flew four Tu-22 Backfire bombers to the Iranian air base, along with a Russian cargo plane loaded with the munitions for the bombers, just hours before the bombers flew their missions. The officials spoke on condition of anonymity because they were not authorized to discuss the matter publicly.
It is virtually unheard of in Iran's recent history to allow a foreign power to use one of its bases to stage attacks. Russia has also never used the territory of another country in the Middle East for its operations inside Syria, where it has been carrying out an aerial campaign in support of Assad's government for nearly a year.
Tuesday's action suggests cooperation on the highest levels between Moscow and Tehran, both key allies of the embattled Syrian president, and sends a powerful message to the United States and the Sunni monarchies of the Gulf, which have seen Iran as the arch-enemy.
The Russian move provides a psychological boost for the Assad-Iran-Hezbollah alliance, illustrating that Russia is strategically committed to stay on course in Syria.
It also heralds even more intense Russian bombardment of Syrian cities. Moscow already stands accused of indiscriminate bombing that has killed many civilians in Syria and of using incendiary weapons in civilian areas — a claim that was repeated by Human Rights Watch on Tuesday. Russia denies the charges.
Syrian rebels and opposition activists reacted angrily to the news.
The Russians "are taking advantage of the political vacuum that was left by America and Western countries that withdrew," said Paris-based senior Syrian opposition figure George Sabra. "It is clear today that the Russians are fighting their global war in Syria."
The Russian deployment in Iran comes a day after Russia's defense minister said Moscow and Washington are edging closer to an agreement on Syria that would help defuse the situation in the besieged northern city of Aleppo.
A U.S. official said, however, that discussions with the Russians are still ongoing and no agreement is close.
Russia and the United States have been discussing greater coordination for striking extremists in Syria, but they have been unable to reach agreement on which militant groups could be targeted.
Gerges, the analyst, said the new developments put to rest any hope of coordination between the United States and Russia in Syria. "It is just too poisonous for the Obama administration. Too costly at this particular moment," he said.
In Tehran, the state-run IRNA news agency quoted Ali Shamkhani, the secretary of Iran's Supreme National Security Council, as saying that Tehran and Moscow have exchanged "capacity and possibilities" in the fight against the Islamic State group.
Moscow and Tehran have been expanding their ties in recent months after most of the sanctions against Iran were lifted following the nuclear deal with world powers.
Russian military experts say the deployment of Russian bombers at the Iranian base sharply cuts the distance to targets in Syria, allowing them to carry a bigger load of bombs.
The bombers previously have flown from their base in Mozdok in southern Russia, and had to cover more than 2,000 kilometers to reach targets in Syria. The distance from Hamedan is less than half that. Russia's Tu-22M3 bomber is capable of carrying more than 20 metric tons of bombs if flown from Iran.
The deployment appeared to stem from political and strategic objectives, rather than military needs.
While flying the warplanes from Hamedan allows Russia to pack a heavier punch in striking the militants' positions, the same job could have been accomplished by flying from the central Syrian air base at Hmeimeem or by increasing the number of bombers flying from Russia.
A top Russian lawmaker, Adm. Vladimir Komoyedov, said Russia's decision to use a base in Iran will help to cut costs, which is "paramount right now."
The Russian ministry statement said the Su-34 and Tu-22M3 bombers targeted the Islamic State group and militants of the al-Qaida-linked group formerly known as the Nusra Front in Aleppo, as well as in Deir el-Zour and Idlib, destroying five major ammunition depots, training camps and three command posts.
The nearest air base to Hamedan is Shahid Nojeh, some 50 kilometers (30 miles) north of the city. Russian aircraft have been reported to land there before. In December, the American Enterprise Institute said in a report based on satellite imagery that a Russian Su-34 "Fullback" strike fighter landed there in late November. It said a Russian Il-76 "Candid" transport plane also landed around the same time before both took off, suggesting the Su-34 may have suffered a mechanical issue.
Iran's constitution, ratified after the 1979 Islamic Revolution, bans the establishment of any foreign military base in the country. However, nothing bars Iranian officials from allowing foreign countries to use an airfield.
The announcement from Russia marks the first significant stationing of its troops there since World War II, when allied British and Soviet forces invaded Iran to secure oil fields and keep Allied supply lines open.
Russia says its bombing campaign in Syria is focused on extremist groups but it has frequently struck other targets, including more moderate rebels fighting Assad's forces. Last week, Russian bombers launched a wave of airstrikes on the city of Raqqa, the Islamic State group's de factor capital in northern Syria, killing at least 20 civilians according to Syrian opposition activists.
Associated Press writers Bassem Mroue in Beirut, Nataliya Vasilyeva and Vladimir Isachenkov in Moscow, Lolita C. Baldor and Robert Burns in Washington, Nasser Karimi in Tehran and Jon Gambrell in Dubai, the United Arab Emirates, contributed to this report.