Hi all this is a little quote I picked up from a site that discusses futuristic weapons OMG this sound VERY devastating the game EndWar for XBOX 360 utilizes this weapon you need to see that trailer.
Well anyways here goes and I quote:
"Among the weapons the Air Force might deploy are space-based lasers, a space plane capable of delivering a half-ton payload anywhere in the world in 45 minutes, and the "rods from god." The rods are currently just a concept--and have been since the early 1980s--but, if the myriad technical and political hurdles to deployment could be overcome, the system could represent a tremendous leap forward in the military's ability to destroy underground, hardened facilities of the type that have allowed Iran and other rogue states to violate the Nuclear Proliferation Treaty with impunity.

HOW DO THE RODS WORK? The system would likely be comprised of tandem satellites, one serving as a communications platform, the other carrying an indeterminate number of tungsten rods, each up to 20 feet in length and 1 foot in diameter. These rods, which could be dropped on a target with as little as 15 minutes notice, would enter the Earth's atmosphere at a speed of 36,000 feet per second--about as fast as a meteor. Upon impact, the rod would be capable of producing all the effects of an earth-penetrating nuclear weapon, without any of the radioactive fallout. This type of weapon relies on kinetic energy, rather than high-explosives, to generate destructive force (as do smart spears, another weapon system which would rely on tungsten rods, though not space-based).

Clearly the rods are a first-strike, offensive weapon. The nation's aging fleet of ICBMs, and its more modern Ohio-class submarines--each carrying 24 Trident missiles--will serve as an adequate nuclear deterrent well into the 21st century, but nuclear weapons cannot deter rogue states from developing their own nuclear arsenals. "
from Globalsecurity.org