These anxieties are further justified in light of the anti-Western rhetoric that was injected in Shoigu’s visit by Iranian Defense Minister Hossein Dehghan. “Iran and Russia are able to confront the expansionist intervention and greed of the United States through cooperation, synergy and activating strategic potential capacities,” Dehghan said, going on to assert that Iran and Russia have common political, regional, and global aims.

According to the Missile Threat website, the January 20 security agreement turns Russia into Iran’s primary supplier of advanced weapons systems. Furthermore, the agreement appears to have settled an eight-year dispute over the S-300 missile system that Russia sold to Iran in 2007 but did not deliver amidst sanctions threats and outcry from the United States and Israel. 

Missile Threat suggests that Iran will now have access to that system, but the site adds that developments in Israeli arms since then have greatly diminished the threat of the S-300. However, if the new arrangement does prompt Russia to make shipments that it was previously constrained from making, the S-300 may be followed up by sale of the S-400 missile system and other advanced armaments. This in turn would signify that the security agreement between the two countries does indeed serve to diminish the potential impact of sanctions on both of them.

Mutual support may encourage Iran and Russia to continue with the foreign adventurism that has been the subject of some of those sanctions, at least in the case of Russia. But thus far, the West has not confronted either country over their mutual support of the Assad regime in Syria. The new security agreement may make it more challenging to do so in the future, as its explicit terms signify greater ease of Iranian-Russian coordination in foreign military actions.

While it remains to be seen whether there will in fact be more such coordination in Syria, it is clear that Iran has every intention of maintaining or further expanding its involvement there. Iran’s state-affiliated Tasnim News Agency reported that Brigadier General Mostafa Izadi, the deputy chief of staff of the Iranian armed forces, committed to this continued involvement on Wednesday. He characterized Iran’s support for Assad as “intellectual and advisory assistance,” but his comments came on the sidelines of the funeral procession for Revolutionary Guard Brigadier General Mohammad Ali Allahdadi, who is the third high-ranking Iranian official to be killed in fighting abroad in the past month. This has cited by opponents of the regime as evidence of the large scale of Iranian involvement in combat in Syria and Iraq.

Indeed, it has been widely reported that in Syria, Iran has been personally responsible for the transformation of the Syrian armed forces into a National Defense Force that is populated mostly by Shiite militias under Iranian control. As former Syrian General Manaf Tlass put it in December, Assad “sold Syria to the Iranians.”

Among the Shiite forces fighting on Iran’s behalf in Syria, one of them is the long-time Lebanese proxy for Iran, Hezbollah. Six of its fighters were killed in the same apparent Israeli strike that killed Allahdadi. According to Tasnim, “Hezbollah has been involved in the Syrian government’s battle against the ISIL terrorists since 2012, in an effort to prevent violence spillover into Lebanon.”

But last week, The Tower reported that Hezbollah’s involvement in Syria appears to have directly led to terrorist actions being directed by ISIL affiliates against Lebanese targets. This has reportedly led some of Hezbollah’s local supporters to call for its withdrawal from the conflict, over Iran’s stringent objections.

For its part, Iran’s response to the deaths of its IRGC officials and Hezbollah affiliates has been to threaten the further expansion of the conflict. According to the Times of Israel, senior Revolutionary Guard commander Nasser Soltani spoke at the funeral for Allahdadi in order to explicitly threaten that, “Israel will certainly pay for what it did.”

The destruction of the state of Israel has been a stated goal for the Islamic Republic of Iran throughout its existence, and Tehran’s closeness with foreign proxies and allies like Hezbollah and Bashar al-Assad have served to moves its security apparatus closer to that declared enemy. Revolutionary Guards often phrase announcements of new weapons development in terms of its ability to strike or threaten Israel, and any weapons obtained from an expanded Russian partnership would presumably be promoted in a similar way.