Some Days
A report like this would have been shrug-worthy in 80s: the Soviet Union was constantly arming our enemies in that tug-of-war for global political-cultural dominance. Proxy wars and regional manipulations are, of course, safer than a face-down that would have eventually compelled one side or the other to resort to a devastating nuclear option. What is so confounding now, though, is the question of precisely what the Russians hope to achieve.
Arming Iran is a bad thing for everyone and doesn’t just act as a way to indirectly confront American interests in the Middle East. Arming Iran is a kind of vote for destabilization in the region and an inducement for more American involvement. Iran is openly hostile to the state of Israel and an Iran with a new, robust air defense technology might be tempted to act even more aggressively to destroy Israel and to solidify its regional dominance.
The US could not stand that and would be drawn into a much wider, bloodier war than we saw in Iraq. Coupled with the likelihood of Iran having nuclear weapons capabilities, an Iran-Israel war that pulls in US and perhaps Syrian involvement could be devastating--not directly devastating to the US since it would prove no existential threat to us, but devastating to life and the economic structures of the world.
I would still consider the Iran-Israel war to be unlikely, but the air defense system delivered by the Russians to Iran and the (likely false) sense of security that the system provides, makes it just a little more possible. Why would Russia want this?
This way lies oil-production disruption.
It could just be the profit motive, of course. At almost three quarters of a billion dollars, the arms deal is just one of a continuing series of big money deals between the Russians and Iran. This has been a lucrative relationship for the Russians.
A little conspiracy-theory thinking, though, may provide a different explanation.
Russia may no longer seek global political dominance in any direct sense, but the desire for economic dominance and greater political influence still exists. They may have lost the Cold War, but they haven’t retired from global politics.
Oil production in Russia is bigger than you might have thought. With recoverable reserves or perhaps 150 billion barrels and its recent ascension to being the biggest oil producer in the world (a position previously held by Saudi Arabia), Russia’s energy security is ensured. If oil prices continue to rise, Russia stands to see monumental monetary gain at the expense of its two biggest rivals: China and the United States.
Any move to destabilize the Middle East, then, becomes a way to greater profit for the Russians and economic pain for her enemies. I would hesitate to say that Russian wants to see a war break out between Iran and Israel, but I would like to point out that another war would engage yet another chunk of America’s military capacity and continue testing our citizens’ capacity to accept lengthy military commitments. The urge to isolationism would be powerful.