Tehran appears to be as convinced as ever that the devastating sanctions on its petroleum industry will be lifted in the near future, and in keeping with this confidence it has made numerous overtures to European businesses that might be interested in receiving exports of Iranian oil and gas. Recently, some of those overtures have been focused on the potential Iranian role in European plans to open new gas corridors that would provide alternatives to Russian fuel in the midst of diplomatic unrest related to the crisis in Ukraine.

But this might not be as simple as it seems at first sight for either party. Radio Free Europe notes that by selling or transporting gas to Europe, Iran could indirectly harm to Russian economy at a time when the two countries are enjoying increasingly close relations, partly characterized by mutual defense and mutual antagonism of Western powers.

Reuters reported on Monday that plans were in development for Moscow to deliver advanced missile systems to Tehran as an alternative to the S-300 missile delivery that was scrapped in 2010 amidst diplomatic pressure from the US and Europe. Earlier this month, a memorandum of understanding signed between the Iranian and Russian defense ministers led to speculation that the long-stonewalled deal would go through at last, but the latest reports indicate that Iran may be getting a better deal than it had been planning on.

The Antey-2500 missile system currently on offer is said to be capable of targeting fast-moving aircraft and reaching targets up to 1,500 miles away. Sergei Chemezov, the head of the Russia state defense company Rostec said that Tehran had not made a decision yet as to whether to accept the offer. This raises the possibility that Iran is considering the trade-offs between its desired military relationship with Russia and its desired economic relations with the West.

Improvements in military capabilities and missile stockpiles are certainly of importance to the Iranian government, as evidenced by the frequent statements by high-ranking officials lauding the country’s defense capabilities. Iran’s official Fars News Agency reported on one of the latest such statements on Monday when it quoted senior presidential advisor Akbar Torkan as saying that Iran had “managed to achieve great achievements in the defense field” in defiance of the very sanctions that negotiators are working to have overturned.

Comments of this nature potentially complicate European decisions about whether to make early investments in the Iranian oil and gas industries before the nation’s government has proved its willingness to comply with a nuclear agreement and act as a reliable global partner. Fars also referred to comments Rear Admiral Habibollah Sayyari and Iranian Supreme Leader Ayatollah Khamenei referring to the West as “enemies” and indicating an interest in challenging their “extensive investment” in the waters around the Middle East.