Lavrov was defending Russia’s decision to use an air base in Iran to launch bombing raids in Syria. The UN Security Council resolution he cites was passed unanimously by the Security Council on July 20, 2015. Resolution 2231 endorses the comprehensive nuclear deal reached between Iran and six world powers on July 14, 2015, under which Iran agreed to curb its nuclear program in exchange for the lifting of international sanctions. The resolution regulates some military interactions between Iran and other countries, including the supply, sale, or transfer of military technologies. Crucially, the text prohibits the supply, sale, or transfer of combat aircraft “for the use in or benefit of Iran” – unless approved of in advance by the Security Council.
Washington has not said outright that Russia's use of Iran’s Shahid Nojeh air base some 50 kilometers north of Hamadan is a violation of resolution 2231. On August 16, U.S. State Department spokesman Mark Toner said “it could very well be a violation,” but that the department’s attorneys were examining the matter and had not yet drawn any conclusions.
A day later, Lavrov said Russian aircraft had been flying out of Iran as part of the what Moscow terms its counterterrorist operation in Syria. He stressed no aircraft or supplies had been transferred to Tehran.
On August 17, an Iranian official said Russian warplanes are only using the Hamadan air base for refueling.
Mark Fitzpatrick, director of the Nonproliferation and Disarmament Program at the London-based International Institute for Strategic Studies (IISS), told Polygraph.info that Lavrov is “mostly right.”
“UNSCR 2231 bans the supply to Iran of major conventional weapons; it doesn’t explicitly prohibit foreign use of Iranian military facilities,” Fitzpatrick explained in an email response.
Fitzpatrick, however, added that the issue is a bit tricky.
“But basing Russian aircraft in Iran would inevitably involve bringing in some supplies and equipment that could end up in Iranian hands or otherwise assist Iran’s military forces,” Fitzpatrick explained.
Anthony Cordesman, a senior analyst at the Washington-based Center for Strategic and International Studies, said any Russian violation of UN Security Council resolution 2231 would hinge on “the transfer of some military capability or skill.”
“The State Department has made it clear that simply using an Iranian base is not a violation,” Cordesman told Polygraph.info.
“The issue is the transfer of some military capability or skill. It is not clear any meaningful transfer will take place, and State is still reviewing the issue.”