Last week, Col. Gen. Alexander Zelin, commander of the Russian air force, announced that Moscow had deployed a state-of-the-art S-300 (SA-20 Favorit variant) long-range air-defense system in Abkhazia, a region of the Republic of Georgia that Russia has occupied since the August 2008 war.

Since then, Russia has recognized breakaway Abkhazia and South Ossetia as independent republics. According to Gen. Zelin, the task of the air-defense system is "to prevent violation of Abkhaz and South Ossetian airspace and to destroy any aircraft intruding into their airspace no matter what their purpose might be." On Saturday, Gen. Zelin announced that the Russian air force had resumed flights from the Abkhazian capital of Sukhumi.

However, there is much more than defense of Abkhazia to the Russian deployment.

In Eurasia, Moscow is using its entire geopolitical toolbox to shift the balance of power in the region. Its tools include diplomacy (including recognition of the self-proclaimed republics), strategic-information operations, arms sales, status-of-forces agreements, base construction - even regime change - to secure its "sphere of exclusive interests."

Taken together with the air force deployment and S-300 base in Armenia, it brings the strategic airspace over South Caucasus and parts of the Black Sea under further Russian control.

The response from the Obama administration was limp. P.J. Crowley, U.S. assistant secretary of state and a State Department spokesman, said: "I believe it's our understanding that Russia has had S-300 missiles in Abkhazia for the past two years." He later claimed that this is "not necessarily" a new development. This is another example of the Obama administration's "Don't let your missiles interfere with my reset policy" approach.

However, with this move, Russia is again flagrantly violating the August 2008 cease-fire agreement negotiated by French President Nicolas Sarkozy. The agreement calls upon both countries to withdraw troops to pre-war positions and restorethestatus quo antebellum. Yet Russia also has built up to five military bases in Abkhazia and South Ossetia in the past two years alone.

The deployment of the system, which has a range of about 120 miles, has to be seen in the context of recent Russian policies in the Caucasus. Moscow recently has negotiated an extension of a contract for basing troops in the Armenian Gyumri military base till 2042. It will assume joint control over Armenian borders. As the leading member of the Collective Security Treaty Organization, Russia controls airspace over Armenia. Now Moscow reportedly is selling an S-300 air-defense system to Azerbaijan.

There is a clear strategy behind these actions. While Secretary of State Hillary Rodham Clinton hails "soft power" in the Caucasus, Moscow engages in a hard, classic political-military power projection in this strategic region, which connects the Atlantic (via the Black Sea and Mediterranean) with the energy riches of Eurasia. As Russian President Dmitry Medvedev stated in his postwar 2008 speech, this is "a zone of Russian exclusive interests" where it is willing to use force.

Most important from a U.S. perspective, Russian actions are aimed at denying the United States airspace and overflight options. The surveillance aspect is no less important; depending on the actual deployment of the air defenses, associated radars will be able to picture or "paint" much of western Georgia and the adjoining Black Sea coastline. Of course, this has implications if the United States decides that Iran leaves it no choice but to use force to neutralize Iran's military-nuclear program. Yet the ultimate objective for Moscow remains to become an uncontested hegemon in the South Caucasus.

The administration's make-believe Realpolitik approach of "see no evil" encourages Moscow to expand its hegemony in the former Soviet space. Such policy inevitably will produce a massive loss of American influence in Eurasia that will take years, if not decades, to recover.

The Russians are committed to deployments in the Caucasus that lead to the strategic denial of U.S. power projection in that region. This bears on the United States' future ability to resupply Afghanistan, to use power to disarm a nuclear Iran, to ensure a reliable energy supply from the Caspian and to help pro-Western friends and allies.

These are hardly great accomplishment for the Obama "reset" policy.

Ariel Cohen is senior research fellow in Russian and Eurasian studies and international energy policy at the Kathryn and Shelby Cullom Davis Institute for International Policy at the Heritage Foundation.