As Russian President Vladimir Putin has shown in Crimea and eastern Ukraine, he’s willing to take an economic hit to expand his political influence.

He’s taking the same approach with Iran, Bloomberg website reported on Wednesday.

Lifting sanctions and allowing Iranian oil onto global markets would threaten to deepen the plunge in crude prices, curbing revenue from Russia’s biggest export. The cost: about $27 billion, based on estimates from the central bank in Moscow.

“The strategic benefits are much more important for Russia,” said Nikolay Kozhanov, an expert at the Royal Institute of International Affairs in London and a nonresident fellow at the Carnegie Moscow Center. “Incorporating Iran into pro-Moscow organizations, Russia is hoping to secure its share in this market or divide zones of influence.”

Putin will get an opportunity to bolster an ally, stymie regional adversaries and open business opportunities. The approach was underscored by his decision this week to lift a ban on shipping S-300 air-defense missile systems to Tehran under an $800 million contract.