The U.S. Army is apparently revisiting a business it abandoned decades ago--long-range strike.
At Aviation Week's Ares defense blog, Bill Sweetman explains that the Army is making a renewed bid for a part of that mission, under the Pentagon's Prompt Global Strike (PGS) initiative.
The program calls for a weapons system that can hit any point on earth within one hour of the launch order. If DoD buys off on the Army's plan to meet that requirement--and that's a mighty big "if"--then the artillery corps could wind up with a role in long-range strike, traditionally the domain of the Air Force and the Navy.
To meet the demands of the PGS mission, the Army is proposing a hypersonic glide vehicle (HGV), most likely armed with a conventional warhead. Launched by a rocket or missile, the HGV separates from its booster and flies a relatively flat trajectory over vast distances, so it cannot be mistaken for an Intercontinental Ballistic Missile (ICBM), or a Submarine-Launched Ballistic Missile (SLBM).
While both the USAF and Navy have suggested conventional warheads for their land and sub-based ballistic missiles, that proposal has a major problem. There is no way to distinguish a conventional ICBM or SLBM from those carrying nuclear warheads. That raises fears that a strike by conventionally-armed ICBMs or SLBMs might accidentally trigger a nuclear war.
The HGV offers other advantages as well. Hurtling toward its target at speeds approaching Mach 10, an HGV is immune to the current generation of missile defenses. And, it's virtually impossible to detect with existing missile warning warning radars, which are optimized for the ballistic threat.
Forward-based at locations like Guam or Diego Garcia, the HGV would more than satisfy PGS mission requirements, allowing the U.s. to strike targets quickly, and with virtually no warning. But selling an Army HGV as at least a partial solution for PGS is a very tall order, indeed.
For starters, the Air Force is dead-set against the plan. Not only does the service have its own HGV research program, there's also the little matter of roles and missions. More than 50 years ago, the Pentagon ruled that any missile with a range of more than 200 miles would be an Air Force responsibility.
Of course, there were some notable exceptions to that rule. The memorandum that imposed the range restriction was actually rescinded in 1958 and over the decades that followed, the Army operated several missiles systems with extended ranges, most notably the Pershing I and Pershing II. So, there is a precedent for the Army controlling and operating strike systems that can reach beyond the operational battlefield.
But the Army HGV faces obstacles go well beyond Air Force opposition. From an arms-control standpoint, HGVs are extremely destabilizing, given their ability to penetrate missile defenses and avoid detection systems. While Russia is already working on its own HGV, it has not operationally deployed the system. The Army plan could give Russia the green light to proceed with full-scale HGV development, forcing us to spend billions more on new warning systems and upgraded BMD weaponry.
On the other hand, developing HGV technology is a good way to demonstrate U.S. resolve, and show Moscow the potential consequences of pursuing those systems. A final decision on PGS is still several years away; that gives the Army more time to work on the proposal and make its best case for sharing the long-range strike mission.