Russia did not even wait a day after the announcement that Poland had agreed to station 10 U.S. anti-ICBM Ground-Based Mid-course Interceptors on its territory before announcing it would target Poland with its own missiles in response.

U.S. Secretary of State Condoleezza Rice signed her historic agreement with the Polish government in Warsaw Wednesday to build the base. As we have repeatedly documented in this column over the past year, the immediate Russian response is likely to be the deployment of a much larger number of Iskander short-range, solid fuel, quasi-ballistic missiles in the Russian and former Soviet enclave of Kaliningrad on Poland's northeast border.

The Poles knew this would likely be the Kremlin's reaction. That's why the agreement will include a U.S. commitment to deploy at least one and probably more batteries of Patriot PAC-3 anti-ballistic missile interceptors on Polish territory.

The 10 GBIs will be deployed to shoot down fast, high-flying intercontinental ballistic missiles that Iran or some other Middle Eastern "rogue state" might launch against the cities of Western Europe or the Eastern seaboard of the United States. The Patriots are designed to shoot down much more numerous, but somewhat slower and far lower-flying short-range ballistic missiles such as the Iskander.

The GBIs would be the best and possibly only chance to prevent New York, Washington, Boston or Philadelphia from being incinerated by a long-range Iranian ICBM fired on a great circle route across Europe and the Atlantic Ocean, if either Iranian President Mahmoud Ahmadinejad or his successors got their hands on those kinds of weapons and were reckless enough to use them.

Russia, however, has persisted in interpreting the deployment of the GBIs in Poland or elsewhere in Central Europe as evidence of a U.S. intention to neutralize its own mighty Strategic Missile Forces. However, only 10 expensive and difficult-to-build GBIs could pose no conceivable threat to the offensive power of the SMF with their 4,700 nuclear warheads.

The Russians counter that if the United States were ever to launch a massive pre-emptive nuclear strike at Russia, annihilating most of its land-based Strategic Missile Forces, those 10 interceptors could make a big difference to the few Russian ICBMs that might survive such a holocaust.

However, Russia's strategic nuclear delivery systems are not just mobile and land-based in the Russian Federation; they are also carried on nuclear submarines and long-range bombers such as the supersonic Tupolev Tu-160 White Swan -- NATO designation Blackjack.

Poland's agreement to host the GBI base -- which is to be built by Boeing -- and the anticipated but still fierce Russian reaction therefore look likely to further heighten the tensions caused by the mini-war in the former Soviet republic of Georgia earlier this month when Russian ground forces easily smashed the ground forces of the small state of 4.4 million people and ejected Georgian troops from the Russian-backed enclave of South Ossetia.

The U.S. case for building the BMD base is very real. But the danger of Russian reactions to it is very real, too. No one in the West dreamed the Russians would dare invade Georgian territory over land after the Georgians launched an armored column to attack the South Ossetian capital of Tskhinvali two weeks ago. But the Russian army did invade and scattered the Georgian forces in a matter of days.

Now, for the first time in the nearly 21 years since U.S. President Ronald Reagan and the last Soviet President Mikhail Gorbachev signed the Intermediate Nuclear Forces Treaty in Washington in December 1987, the United States and Russia look likely to embark on a new ballistic missile and anti-ballistic missile arms race in Europe. The balance of power is making a comeback.