The author warns that a single Iranian nuclear missile could be strategically launched over a dense population and economic center in a way that would devastate the U.S. economically and strategically. He argues for multi-layered space-based missile defense as the most robust solution.

A U.S. DSP military satellite used to track enemy missiles stopped working in mid-September, underscoring the urgent need to keep a program for replacement satellites on track, according to defense analysts.

Working in secret, Israel and Germany have jointly developed a nuclear missile detection system, according to the Defense News Web site. Code-named Project Bluebird, the system is based on the prototype of an aerial infrared sensor designed to identify a nuclear-tipped missile speeding toward a target amid a cluster of decoy missiles.

A senior Pentagon advisory group, in a series of bluntly worded briefings, is warning President-elect Barack Obama that the Defense Department's current budget is "not sustainable," and he must scale back or eliminate some of the military's most prized weapons programs, including missile defense and space weapons.

Russian leaders have decided essentially to put U.S. relations on hold until President-elect Barack Obama takes office in January, signaling the end to Bush administration proposals on missile defense and strategic arms control.

The Defense Science Board released a sobering report that called for the incoming Obama administration to focus on a small but complex set of defense issues, with protection of the country against weapons of mass destruction as the top priority of the new secretary of defense.

In a wide-ranging attack on the United States as it elected a new president, the Russian leader Dmitri A. Medvedev warned that Moscow might deploy short-range missiles in the Baltic region to counter a perceived threat from a proposed American missile defense shield in Eastern Europe. The U.S. has stated that the missile defense system is needed to intercept missiles from states including Iran and does not threaten Russia.

Congress voted recently to approve $5 million for a study of space-based missile defenses, the first time the development of space weapons will be considered since similar work was canceled in the 1990s.

The South Korean military has been placed on alert, according to media reports in the country, after a American satellite detected launch preparations for what appeared to be 10 short-range missiles at Chodo, a navy base.

The Pentagon's missile-defense program has already cost $100 billion and strained relations with the Russians, and it has yet to prove its real-world value. Hitting a bullet with a bullet -- the heart of the system -- is a difficult enough task. But a new report from the U.S. Government Accounting Office reveals that the Pentagon is even having problems launching the practice targets needed to test the system.