"Press reports today quoted an unnamed U.S. defense official as saying that the United States has 'activated' its ground-based missile defense system in response to concerns about a possible test launch of a missile by North Korea.

"While it is not clear what 'activating' the system means or would entail, this term is clearly intended to imply that the system would provide some defensive capability.

"However, the missile defense system has no demonstrated capability to intercept a missile, and statements about 'activating' the system are simply rhetorical posturing.

"The United States should not imply that it has a defensive capability that may be completely illusory. Suggesting to political and military leaders that they have a military capability they do not actually have can be dangerous because it suggests they have options they do not in fact have.

"The U.S. missile defense system remains in early stages of development and testing. Despite the enormous complexity of the system, it has undergone fewer than a dozen intercept tests. The last successful test was three and half years ago, in October 2002; the system has failed in its last three intercept tests.

"Moreover, while the U.S. has fielded eleven interceptor missiles as part of the system, that interceptor design is unproven—it has never been flown in a flight test against a target that it was intended to intercept.

"In addition, all tests to date were highly simplified and did not simulate realistic conditions that would be expected in an actual attack. This is also the case for future planned tests, which will not incorporate realistic countermeasures-such as decoy balloons—to which the system is inherently vulnerable."