Russian President Vladimir V. Putin's warning that Russia might react to even a limited American missile defense system by upgrading its own nuclear arsenal is a reminder that the Bush administration, as it focuses on the benefits of a missile shield, also should be mindful of the potential cost.
Putin's warning centered on the possibility of American withdrawal from the 1972 Antiballistic Missile Treaty, a cornerstone of disarmament efforts that also limits both testing and deployment of defensive systems. If the United States abrogates that treaty, experts note, Russia and other countries are going to take steps to protect their own security interests.
Putin's comments need to be understood in context. A week earlier, Putin and President Bush were praising each other, keenly aware that they were playing to a European audience. Upon returning home, each man spoke to his respective domestic audience.
Speaking for Bush, national security adviser Condoleezza Rice said the United States will do what it wants, regardless of what the Russians have to say. Putin, on the other hand, reminded people that the United States should keep in mind Russia's interests - speaking to his own domestic audience, and emphasizing Russia's continued world importance. Putin wanted to remind the Bush administration that he has other options, rather than simply to submit to what the Bush administration does.
In short, American abrogation of the ABM Treaty - especially if that is done prematurely, before the scope of anti-missile testing "bumps up" against ABM limitations a couple of years from now - is risky business. It hazards a carefully constructed system for the reduction of nuclear weaponry, and it does so in favor of technologies that have so far been unimpressive in limited testing.
Bush has not yet said exactly what kind of missile defense he wants to build, how the United States will proceed to build it, or how long all this will take. He is, however, rushing to fulfill a campaign promise, made back when Republicans insisted that we only needed the will to build a missile defense.
This technology isn't just sitting on the shelf waiting for the political courage to deploy it. A lot will depend on what the Bush administration proposes to do - which officials have been scrambling to figure out. The price for that effort, though, should not be measured in an expanded Russian arsenal of attack missiles and multiple warheads, to make sure it retains the power to overwhelm any shield that could give America an edge.
The bottom line for any governmental action is to make the United States and its people more secure, not less. A limited shield to meet small-scale "rogue state" attacks may make increasing sense as such states move toward long-range missile capability. The idea is gaining political support, but it must be based on proven technology - and it ought to be carefully negotiated with current nuclear arms treaty partners, and not simply imposed as a likely trigger to another arms race.