The talks didn’t produce any breakthrough, but the real news may be that both sides actually seem serious about exploring a joint framework for deployment of a missile defense system in Europe—a program that Russia until late last year regarded as a unthinkable threat to its national security.

The talks were outlined Thursday by Dmitry Rogozin, Russia’s special envoy on missile defense, and Sergey Ryabkov, the deputy foreign minister. The fact that the Russian side wanted to talk with a journalist about their discussions was unusual in itself—another small sign that the “reset” in Russian-American relations pressed by President Obama over the last two years has brought some real changes to the relationship.

Rogozin began by explaining all the reasons why a joint missile defense system made sense—which, given his tough-guy reputation, was encouraging. The problem, he said, was that the two sides couldn’t cooperate unless they trusted each other, and that trust couldn’t come without cooperation. Russia wanted to “break the vicious circle” and get “inside the system.” But how to do that?

Russia wants to be a real partner in the missile-defense system, Rogozin said, rather than a “passive observer” watching American operations, like “a tourist visiting a planetarium.” He said the missile-defense system should be proportional to the threat, which the U.S. says is chiefly from Iran. If so, he said, then why would the U.S. need to deploy advanced anti-missile systems late in this decade, at the end the four-phase project, that seem more suited to stopping Russian than Iranian attacks.

An avid hunter, Rogozin argued that the Americans were claiming they just wanted to shoot rabbits, but were proposing to carry guns that could bring down a bear.

Ryabkov said Russia would like a formal, legally binding assurance that the missile defense system couldn’t be used against its forces. But he recognized that the administration was unlikely provide such a treaty-like document, for political reasons. Perhaps it’s an issue the Russians eventually would agree to finesse.

To allay Russian concerns that the system is aimed at them, the Obama administration has proposed collaboration through two joint centers. The first of the centers would fuse data collected from radars and other sensors deployed by Russia and the U.S., so that both sides could see all the information. The second would be a joint operations center where military officers would plan for different scenarios.

For a journalist like me who grew up in the Cold War years, the idea that the two countries could someday operate joint strategic facilities—sharing top-secret radar and satellite imagery, even--is mind-bending, to say the least.