copyright 2009, The Washington Post WASHINGTON -- A breakthrough that enables the early targeting of ballistic missiles by linking radars and other sensors from different parts of the world is key to the Obama administration's new missile defense plans, according to senior administration officials. The administration announced last month that it would scrap a Bush-era plan to protect European countries and American troops stationed there from any potential Iranian missile attack. Instead of putting 10 interceptors in Poland and radar in the Czech Republic to counter intercontinental missiles, officials said, they would focus on containing Iran's ability to fire short- and medium-range ballistic missiles. Lt. Gen. Patrick O'Reilly, director of the Pentagon's Missile Defense Agency, defended that decision Wednesday, saying that the linking of U.S. and allied radar systems with satellites and other sensors would allow officials to follow the path of launched missiles throughout their flight. 'This capability did not exist five years ago,' O'Reilly said at a symposium sponsored by the Atlantic Council, a nonpartisan think tank. He said the first elements of the system would be operational aboard some warships by 2011. By 2015, he added, the goal is to base additional SM-3 interceptor missiles on land. The undersecretary of state for arms control and international security, Ellen Tauscher, appearing at the same event, said discussions are already under way with Poland to base missiles there, and talks have begun with the Czech Republic about making it the headquarters for command and control elements associated with the system. Tauscher said European allies, who were initially troubled by the hasty announcement canceling the George W. Bush-era system, have come to support the Obama administration's plan, which would permit earlier deployment and provide wider coverage than the earlier one. 'Remember, this is a NATO-wide European missile defense system as opposed to a bilateral missile defense system,' she said. Tauscher also said there would be additional opportunities for allied countries to participate in missile defense. Another land-based radar system, which was also part of the Bush plan, for example, will need to be located in southeastern Europe. O'Reilly said the new missile defense plan would be less costly and would allow for many more defensive missiles to be deployed. Under the tentative plan, 30 SM-3 interceptor missiles would be located in Poland at a cost of $10 million each; under the earlier plan, there would have been 10 interceptor missiles there at a cost of $70 million each. O'Reilly added that preparation of a Polish missile defense site, which was to have taken five years to complete, could now be finished in less than a year and be staffed with fewer than 100 U.S. personnel, instead of the 400 who would have been needed under the Bush-era plan. 