In one key conflict area-Iran-President Barack Obama appears to be keeping, at least for the moment, his campaign commitment to engage rather than threaten, to use diplomacy rather than force.

As talks with Iran go forward, hope continues to rise for serious diplomacy that could, just maybe, lead us a few steps closer to the “world without nuclear weapons” that Obama has called for.

But achieving that goal means more than just talking, as earlier administrations always did, of preventing other countries from obtaining nukes. It means recognizing-and implementing-Washington’s own obligations under the Non-Proliferation Treaty, obligations to move towards complete nuclear disarmament. That was the treaty’s deal: Countries without nuclear weapons, like Iran, agreed not to seek or make such weapons, in return for access to nuclear power and nuclear technology for peaceful uses, and for a commitment by the Nuke Five (the U.S., Britain, China, France and Russia) to get rid of their nuclear weapons once and for all.

Reaffirming that commitment to our own nuclear disarmament should be the starting point of any U.S. negotiations over anyone else’s

If negotiations with Iran mean Washington simply goes through the motions, just to be able to say “we tried” before escalating to harsher sanctions or even military strikes later on, diplomacy doesn’t stand a chance.

So what should real nuclear engagement with Iran seek? One great medium-term goal would be the creation of a Nuclear Weapons-Free Zone across the entire over-armed and volatile Middle East. A number of countries in the region have argued for such a zone for years, including U.S. allies such as Egypt. Iran would almost certainly be very interested.

But there’s already a powerful nuclear weapons arsenal in the Middle East, whose very existence is instigating a regional nuclear arms race, and undermining non-proliferation efforts. That arsenal belongs to one of the small group of outlaw countries that have refused even to sign the Non-Proliferation Treaty. Its arsenal is widely known, but not officially acknowledged, and the UN’s nuclear watchdog agency has never been allowed to inspect the hundreds of high-density nuclear bombs.

That country is Israel. And Obama, so far, has accepted Israel’s policy of “strategic ambiguity,” in which Tel Aviv refuses to acknowledge its nuclear arsenal. Israel rejects a nuclear weapons-free zone, because it would mean having to open its nukes to immediate international inspection and then quickly getting rid of them. Other countries that built and tested nuclear weapons, such as India and Pakistan in 1998, faced serious U.S. sanctions. But the U.S. refuses to hold Israel accountable for its dangerous nuclear weapons.

Regional nuclear weapons-free zones-which exist all over the world-help build global campaigns to strengthen disarmament and international law. A nuclear weapons-free zone in the Middle East would mean Israel would have to get rid of its nukes. Iran, Egypt, Saudi Arabia, and everyone else in the region would have to continue their current obligation not to create nuclear weapons. And the U.S. would be prohibited from sending nuclear weapons on ships, subs or planes into the no-nuke zone.

The great secret is that support for such a nuclear weapons-free zone in the Middle East is already U.S. policy. In 1991, in the United Nations resolution ending the Gulf War, the U.S. included a call for “establishing in the Middle East a zone free of weapons of mass destruction and all missiles to deliver them.” The whole region-no exceptions. And UN Security Council resolutions are binding, so now it’s the law-for the U.S. and the whole world.

A nuclear weapons-free zone would allow everyone in the Middle East to sleep a little better. And it would make future negotiations-over issues including Iran’s nuclear power facilities and the Palestinian-Israeli conflict-much more likely to succeed.