But the administration is not pursuing that capability because it does not believe it is feasible, according to one senior defense official.
The military has considered deploying interceptors on ships, but the Navy has safety concerns that have not yet been resolved. The suggestion of attempting intercepts from ships on the North Sea probably would aggravate tensions with Russia. That could put it right in the path that some Russian ICBMs would use, further reinforcing Russia's belief that it, not Iran, is the target of the system.
The GAO investigators also took the administration to task for not conducting studies earlier that could have revealed the problems. Reports by the GAO and scientific bodies advising the government have raised other concerns about the missile shield, citing production glitches, cost overruns, problems with radars and sensors that cannot distinguish between warheads and other objects.
One report by the National Academy of Sciences recommended canceling the fourth phase of the system and deploying the interceptors to the East Coast.
The GAO study was requested by Rep. Michael Turner, R-Ohio, who until recently led a panel that oversees missile defense. He said he is concerned that the interceptor in development might be useless in protecting the United States.
"This report really confirms what I have said all along: that this was a hurried proposal by the president," he said.
Missile Defense Agency: http://www.mda.mil/system/system.html
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