Secret Defense Department studies cast doubt on whether a multibillion-dollar missile defense system planned for Europe will ever be able to protect the U.S. from Iranian missiles as intended.
Military officials say they believe the problems can be overcome and are moving forward. But proposed fixes could be difficult.
The studies are the latest to highlight serious problems for a plan that has been criticized on several fronts. Republicans claim it was hastily drawn in an attempt to appease Russia. But Russia is also critical of the plan, which it believes is really intended to counter its missiles.
The classified studies were summarized in a briefing for lawmakers by the nonpartisan Government Accountability Office. The briefing, which was not classified, was obtained by The Associated Press.