It's unlikely the neighbors would complain if a family installed an alarm system. Especially if the family offered to install alarms in every home on the block. Such a generous offer would protect everyone from crime. Friendly, law-abiding neighbors would realize they have everything to gain and nothing to fear.

The Bush administration wants to install the military equivalent of a series of home alarms in Eastern Europe. Yet one of the neighbors raised a fuss.

Here's the background: The United States wants to build a missile-defense system that would include 10 interceptor missiles based in Poland and a radar center in the Czech Republic. President Bush recently visited both countries to discuss these plans, and the feedback from their leaders was good. "Of course, we discussed the deployment of a U.S. military base in our country and in neighboring Poland, and I believe President Bush and I agree on this issue," Czech President Vaclav Klaus told reporters.

But one neighboring leader objected: Russian President Vladimir Putin. The proposed missile-defense screen would lead to an "inevitable arms race," he warned, adding, "If the American nuclear potential grows in European territory, we have to give ourselves new targets in Europe."

Nuclear potential? Targets? That's an odd way to describe a defensive program that would actually protect nations. And in fact, Putin seemed to later see the error of his stance, going so far late last week as to volunteer to take part in the defense screen.

Russian cooperation would be a welcome break with the past. During the Cold War, the "arms race" consisted of the United States and Soviet Union building more and more nuclear weapons. That meant missiles, subs, bombers and warheads. But we're talking now about a missile screen, a defense that could protect innocent people from an incoming nuclear weapon.

As many Europeans realize, such a defensive system is necessary. They've lived in a dangerous neighborhood for years. Both world wars started in Europe, followed by a Cold War that saw Eastern Europe under Soviet domination for decades. And the danger isn't all in the past. Today, a potential new threat is rising nearby: Iran.

Tehran's fundamentalist government seems determined to acquire nuclear weapons. Several years ago the French, British and Germans asked Washington to lie low and let them deal with Iran's nuclear ambitions. But their attempts to jawbone Iran into dropping its nuke program have utterly failed. A nuclear Iran seems all but inevitable.

As if to underline the threat, Iran test-fired ballistic missiles last November and again in January.

An American missile-defense system could tip the security balance back in Europe's favor. Surely that doesn't threaten Russia. In fact, it should give Moscow some reassurance.

Our goal is "to safeguard free nations from the possibility of a missile attack launched from a rogue regime," as the president put it. "Russia is not our enemy."

Indeed, Russia should favor such a screen, or at least shouldn't object to it. Poland and the Czech Republic are now members of NATO, and the United States is obligated to do all it can to protect them. Sharing our missile-defense capabilities with our allies is, and will remain, a critical obligation.

For various reasons, some technical and some political, it's taken far longer than it should have to get a missile-defense system deployed. Now that we've finally got the technology working, it's time to share it with our friends and allies. After all, keeping it to ourselves wouldn't be neighborly.

Ed Feulner is president of the Heritage Foundation.