By all indications, Russia is prepared to support sanctions against Iran. Perhaps this is a way of returning a favor to U.S. President Barack Obama for his decision to scrap the missile defense shield intended for Poland and the Czech Republic.

But there are other reasons behind the Kremlin’s decision to change its position on sanctions. In the late 1990s and early 2000s, Moscow always blocked sanctions against Iran. Moscow’s $1 billion contract to help build the Bushehr nuclear reactor supported Russia’s high-tech sector during difficult economic times. Moreover, Iran was ruled during that time by Mohammed Khatami, a moderate who did not threaten his neighbors with military attacks. But after the radical Islamic President Mahmoud Ahmadinejad came to power in 2005, Moscow’s former support of Tehran raised several questions.

The argument that the Kremlin held Iran as its trump card to spite the United States does not hold water. In fact, the opposite is true: Iran took advantage of Russia by leveraging the Bushehr project against the Kremlin’s steady support for Iran in the United Nations. Moreover, Tehran refused to sign the agreement with Russia, Turkmenistan, Kazakhstan and Azerbaijan on the demarcation of the Caspian Sea. At the same time, Iran strengthened its armed forces, particularly its missile capabilities, largely thanks to Russian technology and weapons systems.

Iran does not yet have long-range missiles capable of reaching the United States or Europe, but it does have medium-range missiles, such as the Shahab-3, that can reach Russia’s North Caucasus and the Astrakhan region, as well as Kazakhstan and Armenia, Russia’s allies in the Collective Security Treaty Organization.

The argument that Russia’s support of Iran in its ongoing confrontation with the United States gave the Kremlin clout in the Muslim world is also weak. Iran’s missile and nuclear programs are a direct threat to Moscow’s allies in the Middle East. It was no coincidence that Iran’s nuclear program was question No. 1 during the recent meeting between Foreign Minister Sergei Lavrov and the secretary-general of the Arab League, Amr Moussa, and Turkish Foreign Minister Ahmet Davutoglu.

Most surprising of all, it took a “reset” in U.S.-Russian relations to finally convince the Kremlin that it needs to keep a safe distance from the highly unpredictable and unstable Iranian regime that is located so close to Russia’s borders.

This comment appeared as an editorial in Vedomosti.