President Barack Obama's decision to scrap a controversial "missile shield" in Central Europe is the correct one to make, but, like many difficult decisions, comes with costs. To understand why the decision was the right one, we need to look at the supposed justifications for the missile defense system.
On one hand, the missile system was supposed to protect the U.S. from an Iranian threat. Exactly how it was going to do this was never entirely clear, but the most compelling argument was that the defense system - if it worked - could prevent Iran from exerting influence over the U.S. by threatening Europe with a missile attack. On the other hand, the system was seen as a way of providing important security commitments to our important allies Poland and the Czech Republic.
The problem here, of course, is that East European countries, and especially Poland, are not worried about the Iranians; they are much more worried about the Russians. So the underlying question remained: was the system really aimed at the Russians? We knew this, the Poles knew this, and the Russians knew this; hence the tension this interjected into U.S.-Russian relations.
Furthermore, within Russia the missile defense system was practically a gift on a silver platter to anyone who wanted to stir up or play on anti-American sentiments in an effort to justify a more antagonistic foreign policy towards the U.S. (as well as more nationalistic behavior at home). Given the "unstated" nature of the potential missile defense system, we could never really get into a discussion about whether 10 missile interceptors in Poland would actually have any sort of deterrent effect against any Russian actions. As a corollary, the Russians never had to really provide justification for why they were so angry; they could just define the interceptors as a generic threat to Russian national security.
So the bottom line is as follows: (1) it is unclear how these interceptors would have improved U.S. national security; (2) it is unclear how the interceptors would have improved the security of American allies in Eastern Europe; (3) they would have been expensive (note Obama's mention of "cost-effectiveness" in his statement on the matter); (4) we don't know if they would have worked (note Obama's emphasis on the effectiveness of his proposed alternative); and (5) they would have continued to provide a serious impediment to improving U.S.-Russian relations.
All in all, this does not seem like a program worth going forward with simply because people in the previous administration saw fit to initialize it. When you are the president, you ultimately need to make decisions that will improve the national security of your nation. The proposed missile shield would not have done so.
But let's be clear: this is not a costless decision. Anytime we change our minds on military commitments to allies, there are costs down the road for doing so. Both Poland and the Czech Republic have born serious costs in order to move this plan along with their own populations -- neither of which were uniformly enthusiastic about these proposals, especially in the Czech Republic. I would hope the administration would take damage control in this regard very seriously, and I expect to see details in the coming days about what exactly we are doing to ameliorate the Poles and the Czechs.
Second, there will be political costs for the Obama administration at home, as it will give the Republicans yet another chance to argue that a Democrat is soft on defense. This argument, however, is getting old in the current era, and makes it that much more incumbent upon the administration to explain that this was a decision made with the goal of enhancing national security. Just because people will spin this as a decision to appease the Russians or to prioritize Russian relations over Polish relations does not mean that going forward with the missile shield would have actually improved American national security.
Finally, it is important not to overestimate the effect of this decision on U.S.-Russian relations. Yes, this will remove a thorn from that relationship, and an important thorn at that. And it is possible that we may even see some reciprocal move on Russia's part in terms of ratcheting up pressure on Iran in the coming days; there have long been indications that such a deal might be possible.
But this doesn't mean that other problems in the relationship are going to magically disappear. Moreover, care must be made to convince the Russians of the exact same thing that the American people need to be convinced of -- that this decision was not made to appease Moscow, but rather, that it was in the best interest of U.S. national security. The Russians should take comfort in the fact that the current administration is willing to listen to arguments about the value of particular policy decisions, but they should in no way take away from this an overinflated sense of Russian influence over Washington's foreign policy.