Russia's war of nerves with the West intensified last week with Moscow's formal suspension of its participation in the Conventional Forces in Europe (CFE) treaty. Russia is using the CFE to remind NATO, and its European members in particular, of Moscow's strategic concerns as it hopes to drive a wedge between the two sides of the Atlantic.

The CFE was negotiated toward the end of the Cold War to limit conventional force deployments in Europe and western Russia. It was modified after the collapse of the Soviet Union to reflect the new political landscape, but only Russia ratified the new version. NATO members demanded that Russia first honor its obligations by withdrawing forces from the former Soviet republics of Georgia and Moldova. Russian officials insist all troops are gone — or argue that only peacekeeping missions are in place. They refuse international inspections that would confirm either assertion.

Russia's suspension means that it will stop exchanging information as stipulated by the treaty and it will end foreign inspections. Russian officials deny that any buildup of forces will follow, although there are unconfirmed reports of new troops being deployed to some restive regions.

NATO officials were troubled by the move, and rightly so. While Moscow's intentions are political — it wants to alert Europe to Russian unease with U.S. plans to deploy missile defense systems in the region — the move is much more than that. The CFE is a pillar of stability in Europe and any attempt to undermine the transparency of military operations is bad for the region.

Europe should not be intimidated: History suggests that will only encourage Russian heavy-handedness. NATO should demand that Russia honor its obligations and talk about concerns, rather than threaten. That is, after all, how partners work out their problems.