Iran is big business for Russia. Not only is cash-rich Tehran buying Moscow's nuclear technology and long-range missiles, it is also purchasing assault rifles, specifically, the Kalashnikov AK-103.
The AK-103 is a flexible and deadly weapon. Held like a handgun or, stock extended, from the shoulder, it can fire single shots or, in automatic mode, up to 600 rounds a minute.
And it is designed for add-ons. Telescopic sites with optional night vision, bayonets and even grenade launchers are clipped onto the rifle with no more effort than changing the lens on a camera.
It is, in short, an almost ideal assault rifle. It is so good, and relations with Russia are so strong, the latest shipment of Kalashnikov's might indicate that Moscow is gaining market share in arming Iranian troops.
According to an Israeli service that specializes in weapons-related news, the iHLS, Iran's military troops are primarily armed with two kinds of assault rifles. One of them is the German made Heckler & Koch G3. The other is Russia's Kalashnikov AK-103. Perhaps Russia is just competing to win the German portion of Iran's demand for the guns.
Another possibility, however, is that Iran's demand for such weapons is stretching the abilities of both Germany and Russia to satisfy Tehran's voracious appetite. If so, it is no secret that demand is being driven by the Islamic Republic's commitment to defeat ISIS in Syria, keeping Damascus as a proxy capital to Tehran.
Along with Syria's President Assad, Hezbollah, the so-called "party of Allah" in Lebanon, is also a vassal of Iran. At Tehran's bidding, it too is in the war in Syria.
Eventually ISIS will be defeated there. When it is, it is a virtual certainty that Middle Eastern forces on the ground - Iran, Syria, Hezbollah and perhaps Turkey - will turn their attention to attacking Israel with a view to destroying it.
When they do, Jerusalem is likely to face Russian allies with Russian trained troops and armed with Russian weapons. Along with the Kalashnikov AK-103, will it face Russia too?