Iranian officials sometimes respond to accusations that Tehran is seeking a nuclear weapons capability by replying that, not only do they not want a bomb, they'd actually like to see a nuclear-weapons-free Middle East. Yes, this is surely in part a deflection, meant to shift attention away from concerns about Iran's nuclear activities by not-so-subtly nodding to the one country in the region that does have nuclear weapons: Israel.

But could Iran have a point? Is there something hypocritical about the world tolerating Israel's nuclear arsenal, which the country does not officially acknowledge but has been publicly known for decades, and yet punishing Iran with severe economic sanctions just for its suspected steps toward a weapons program? Even Saudi Arabia, which sees Iran as its implacable enemy and made its accommodations with Israel long ago, often joins Tehran's calls for a "nuclear-free region." And anyone not closely versed in Middle East issues might naturally wonder why the United States would accept Israeli warheads but not an Iranian program.

"This issue comes up in every lecture I give," Joe Cirincione, president of the nuclear nonproliferation-focused Ploughshares Fund, told me. The suspicions that Israel gets special treatment because it's Israel, and that Western countries are unfairly hard on Israel's neighbors, tend to inform how many in the Middle East see the ongoing nuclear disputes. "It is impossible to give a nuclear policy talk in the Middle East without having the questions focus almost entirely on Israel," Cirincione said....