It's not just Iraq. The missile defense shield for western Europe, the Orange Revolution in Ukraine (which was supported by the US, and booted a pro-Russian leader), the Gazprom stuff with Germany, Uzbekistan, Iran, etc.
Which isn't nearly the same as what they're doing, from our perspective, but Russia probably thinks of the bomber exercises as part of the same game, and not that much of an escalation.
It's like they've got international relations Aspergers.