The ambitious U.S. plan to protect Europe from ballistic missiles goes online this week, and Russia is already making clear that a stern, if not outright belligerent, response may be forthcoming.
With Russian jets buzzing U.S. naval vessels with increasing frequency, and major NATO war games scheduled in Poland next month, the formal inauguration of the Aegis Ashore system, based near a village in rural Romania, is likely to further vex already tense relations between Moscow and the West.
A day before the May 12 ceremony, to be attended by U.S. and NATO officials, a Russian Foreign Ministry official called the decision to install the system in Romania a mistake, and said it was a violation of a key Cold War treaty that barred intermediate-range missiles from Europe.
"This move is harmful and wrong, since it may impair strategic stability," Mikhail Ulyanov, who heads the ministry's nonproliferation and arms-control department, was quoted by Interfax as saying on May 11.
"In this sense, our interests, security interests are affected immediately," he added.
The system in Romania, which consists of an Aegis radar and two dozen SM-3 missiles, is the first onshore installation of a larger system that has been deployed on U.S. Navy ships in the Mediterranean for several years now.
U.S. officials have said the entire project -- known as the European Phased Adaptive Approach -- is aimed at intercepting ballistic missiles launched from Iran at European targets. Construction on a similar system in Poland, slated for completion in 2018, will be launched on May 13.
Moscow, however, vehemently opposes the efforts, rejecting U.S. assurances that the system is far too limited to threaten Russian intercontinental ballistic missiles.
Adding to Russia's suspicions is the fact that tensions between the West and Iran have been markedly reduced following the recent deal to curb Tehran's nuclear program.
"The Russians have been saying all along, 'This isn't about Iran, it's about us,'" says Tom Collina, director of policy at the Ploughshares Fund, a Washington-based research group. "This seems to be feeding their concerns."
The start-up of the Romanian battery comes as ties between NATO and Russia continue to fray in the wake of Russia's annexation of Ukraine's Crimea Peninsula two years ago. Russian jets have flown extremely close to U.S. planes and naval ships in the Baltic Sea and elsewhere in recent weeks, prompting warnings from Washington.
In an effort to calm NATO allies like Poland, Hungary, and the Baltic states, U.S. defense leaders also announced earlier this year that three combat brigades would be rotating into Europe on a regular basis. The incoming chief of U.S. forces in Europe has also called for a brigade to be permanently based there.
Defense Minister Sergei Shoigu announced last week the creation of three new military divisions along Russia's western and southwestern borders in response to what he called "the buildup of NATO forces in close proximity to Russia's borders."
U.S. and NATO forces are also slated to hold major military exercises in Poland beginning on June 7, with up to 25,000 troops expected to participate.
The Romanian system has also prompted a specific threat from Moscow, namely the deployment of Iskander missiles to Kaliningrad, the Russian exclave wedged between Poland and Lithuania. With a range of 500 kilometers and the ability to be fitted with either nuclear or conventional warheads, Iskanders would be able threaten much of Poland from Kaliningrad
Some European defense officials have suggested the Iskanders may already be in the territory.
Washington and Moscow have also been at loggerheads over the status of the Intermediate-Range Nuclear Forces Treaty, the 1987 agreement that removed an entire class of cruise and ballistic missiles from Europe.
For the third consecutive year, the United States last month accused Russia of violating the treaty by allegedly developing a ground-launched cruise-missile system. Russia denies the accusation and has asserted the United States itself is in violating the treaty by moving forward with the ballistic-missile-defense system in Romania.
Collina says the Romania radar system feeds into the message that the Kremlin has long sought to convey to the Russian populace -- that NATO and the West are threatening Russia and seeking to encircle it.
"This is a game about posturing. The U.S. deploys the system in Romania, Russia has to say something to assure its people that they've neutralized the system," he says.
"The U.S. is giving Russia a ready excuse to be more belligerent," he adds.