Mr Putin goes to Tehran
So what do we think President Putin is up to? Is he merely cocking a snook at Washington, is his visit simply a way of saying, in effect: "If Iran is your enemy, OK, it's our friend"?
I think it's a bit more complicated than that. For one thing, I don't believe the Kremlin is happy with the idea of a nuclear-capable Islamic republic on its doorstep. For another, Moscow, for all its grand-standing, has in fact been rather subtle, diplomacy-wise, when it comes to UN negotiations over sanctions against Tehran.
And what about the Iranians? Well, on Newshour today, our man in Tehran, Jon Leyne, told me that the Iranians don't trust Mr Putin one little bit. His way of looking at the world is not theirs, and they're perfectly well aware that Moscow could well be using them as a pawn in its game against Washington.
Both the Russians and the Iranians like to think of themselves as regional super-powers. (In Moscow's case, of course, they like to think of themselves as a global super-power as well.) There's as much potential for competition as for cooperation between them -- and I suspect we're going to need to keep a close eye on both capitals as they seek to strengthen their regional alliances.
But if you're in Moscow, Tehran or Washington, I'd be interested to know how it looks to you.