Tehran Bureau has an article taking a look at why the Russian and Chinese leadership are so firmly tied to the hardliners in Iran.
Russia has also exploited the fact that the hardliners in Iran need its protection and assistance. For several years now, it has virtually become a ritual to announce at the beginning of each year that the Bushehr light water nuclear reactor that Russia is constructing will be starting operations by mid-year, and to then postpone that to the end of the year, or early in the following year. Even so, the reactor has not yet become operational.
There has also been much talk about Russia selling an air defense system called S-300 to Iran. The Russians have dazzled Iran’s military with the capabilities of the S-300 system. The capabilities are indeed very significant, to the extent that they have prompted the United States to issue a warning about their sale to Iran. The prospect of the sale has also generated much concern in Israel. Yet, after nearly a decade of dazzling, no sale has been finalized and no system has been delivered to Iran.
The reasons are twofold. Russia treats Iran as a winning card in its relations with the United States. The fact that anti-American hardliners are in power in Iran is to Russia’s advantage. First, because it keeps the U.S. influence in Iran, if any at all, minimal. Second, it forces the United States to focus its attention on Iran, and less elsewhere. At the same time, by not completing the Bushehr reactor and promising to sell it the S-300 system, but not actually going through with the sale, Russia keeps the hardliners in Iran in need. The Iranian public and the reformist-democratic groups in Iran in particular, also see this, which explains their anger at Russia.