From Popular Science, a project that introduces a powerful kinetic weapon to the U.S. military arsenal:
When the order comes, the sub shoots a 65-ton Trident II ballistic missile into the sky. Within 2 minutes, the missile is traveling at more than 20,000 ft. per second. Up and over the oceans and out of the atmosphere it soars for thousands of miles. At the top of its parabola, hanging in space, the Trident’s four warheads separate and begin their screaming descent down toward the planet. Traveling as fast as 13,000 mph, the warheads are filled with scored tungsten rods with twice the strength of steel. Just above the target, the warheads detonate, showering the area with thousands of rods-each one up to 12 times as destructive as a .50-caliber bullet. Anything within 3000 sq. ft. of this whirling, metallic storm is obliterated.
If Pentagon strategists get their way, there will be no place on the planet to hide from such an assault. The plan is part of a program — in slow development since the 1990s, and now quickly coalescing in military circles — called Prompt Global Strike. It will begin with modified Tridents. But eventually, Prompt Global Strike could encompass new generations of aircraft and armaments five times faster than anything in the current American arsenal. One candidate: the X-51 hypersonic cruise missile, which is designed to hit Mach 5 — roughly 3600 mph. The goal, according to the U.S. Strategic Command’s deputy commander Lt. Gen. C. Robert Kehler, is “to strike virtually anywhere on the face of the Earth within 60 minutes.”
The question is whether such an attack can be deployed without triggering World War III: Those tungsten-armed Tridents look, and fly, exactly like the deadliest weapons in the American nuclear arsenal.
The article goes on to list concerns that were brought up by officials in congress and elsewhere — what is it really good for? If the President is going to authorize an ICBM launch, he’d better have a damn good reason to do so. But the need to use a cruise missile implies inaccessability by air. If the target is inaccessible by air, then is the intelligence leading to its selection really that trustworthy? Because this weapon looks like a nuclear missile, it probably has the potential to cause more problems than it solves.