A group of prominent scientists who have been critical of missile defense plans told lawmakers that a system being built by the United States cannot protect the country.

Boeing has said that it will attach sophisticated antennas to its new satellites as part of a broader push - supported by the Pentagon - to counteract concerns that these space assets may be disrupted by terrorists and hostile governments.

The author, a former U.S. intelligence officer and weapons inspector, argues that Russia's new Topol-M ballistic missile has effectively ended the U.S. dream of an effective missile defense.

Russia is moving forward with the development of its new nuclear missile system that is, according to Putin, "unlike any weapon held by other countries". Analysts believe that he is referring to the Topol-M which is capable of manuevering post-launch. This move could be intended as a signal to the United States as Washington pushes forward with a missile defense system.

[ Earlier Story ]

Documents published by the U.S. Missile Defense Agency over the past two years appear to confirm what experts have charged is a fundamental flaw of the Bush administration's national missile defense system: it is vulnerable to cheap countermeasures and decoys.

Russia announced the successful development and testing of a "maneuverable reentry vehicle" ? a technology under development for decades that could provide a rudimentary guidance system for intercontinental missiles and render them difficult or impossible to destroy.

Although the development of Chinese missile defense countermeasures is not likely to keep pace with U.S. technologies, the United States should still monitor China?s efforts, says a report released by the U.S. Army War College?s Strategic Studies Institute.

The U.S. Defense Department has begun work on developing ways to defeat any enemy countermeasures that would hinder a U.S. missile defense system.

Satellite photos show that China has recently test-launched a medium-range ballistic missile equipped with multiple dummy warheads to counter a missile defense system.

Concerns about "emerging missile states" have spurred development of a system to defend the US from small-scale ballistic missile attacks. But the planned system could be compromised by simple countermeasures, and the security costs of deployment could be high.