The United States plans to complete the deployment of its ballistic missile shield in Europe within eight years, thanks to the new START treaty signed with Russia.

Late last week, the Pentagon explained why President Barack Obama scrapped Bush-era plans to deploy elements of the system in Poland and the Czech Republic.

The Czech radar installation and the 10 long-range missile interceptors in Poland would have covered only 75% of Europe’s territory, which U.S. allies said was not enough. The new missile defense shield will cover 100% of Europe, said Bradley Roberts, deputy assistant defense secretary for nuclear and missile defense policy.

The new system is to be deployed within eight years. The first phase, by the end of 2011, stipulates the deployment of a radar, sea-based Aegis missile defense systems and Standard Missile 3 interceptors in southern Europe.

Around 2015, more-advanced interceptors and missile detectors would be fielded in addition to the first land-based SM-3 facility in southern Europe. The final two stages of the shield would see the land and sea fielding of even-more sophisticated versions of SM-3 interceptors that would be able to fly faster and farther to protect Europe and the United States.

U.S. Missile Defense Agency Director Lt. Gen. Patrick O’Reilly said that the long-range interceptors in Poland would have cost $70 million each, whereas a single SM-3 interceptor would cost $10 million to $15 million.

O’Reilly dismissed recent assertions from Republican lawmakers that a new nuclear arms control treaty with Russia would jeopardize plans for missile defenses in Europe.

“The new START treaty actually reduces constraints on the development of the missile defense program,” he said during a hearing in the House Armed Services subcommittee.

The accord, signed in early April by Obama and Russian President Dmitry Medvedev, will permit missile defense tests that had been prescribed under the 1991 Strategic Arms Reduction Treaty, he said.

“Our targets will no longer be subject to START constraints, which limited our use of air-to-surface and waterborne launches of targets which are essential for a cost-effective testing of a missile defense interceptor against medium-range and intermediate-range ballistic missiles in the Pacific region,” O’Reilly said.