Fred Hiatt calls out a friend of mine in the WaPo's lead editorial, and I expect he'll have something to say about it. But let me just note this:
In essence, Mr. Obama promises an improved version of the Bush administration's three-year-old strategy of offering, in conjunction with European allies and Russia, economic and political favors to Iran in exchange for an end to its nuclear program and threatening it with sanctions if it refuses.
All this proves is that if you describe policy ideas at a sufficient level of abstraction, then everything is identical. But the difference here is pretty clear. Obama would like to work, in good faith, for a diplomatic agreement that would achieve America's key security goal (verifiable Iranian disarmament) in exchange for us offering some kind of concessions to Iran. Bush and McCain, by contrast, come from a school of thought which regards it as essentially impossible to reach stable agreements with "bad guy" regimes.
Thus, their diplomatic approach to Iran amounts to repeatedly shaking their fists at Iran and demanding that they capitulate, followed by stern proclamations about how "unacceptable" a nuclear-armed Iran would be. It's not clear if the Bush-McCain policy is going to lead to war (as a literal read of their rhetoric would suggest) or to Iran possessing nuclear weapons (if they flinch from launching a war) but what it's not going to do is produce a diplomatic agreement to achieve verifiable nuclear disarmament in Iran. Obama, by contrast, wants to pursue good-faith negotiations aimed at achieving that goal. That's the difference and it's a huge difference -- to brush it all away because both candidates agendas involve "Europe," "Russia," and "Iran" is silly, especially given that both McCain and Obama say they believe they're disagreeing it ought to take compelling evidence before anyone concludes otherwise.
[The less said about Hiatt's concluding pitch for endless war in Iraq, the better]