Azerbaijan has bought oil and natural gas from Russia to meet internal demand while exporting its own energy riches to the West. Russia also has been the main market for Azerbaijan’s fruit and vegetable exports. It also is a key transport corridor for Russia’s trade with Iran and other partners in the Middle East.

Once strategic partners in the post-Soviet order, Russia and Azerbaijan are drifting into open hostility. From diplomatic snubs to deaths in custody and geopolitical realignments, ties between Moscow and Baku are under unprecedented strain.

The rift, provoked by the deaths of two ethnic Azerbaijanis in Russian custody, was the latest in a series of spats that revealed a deeper diplomatic rift between the former allies.