Recently, our partner Front Line Defence published a piece on the disruptive potential of hypersonic weapons and we republish here.
General James E. Cartwright, who holds the Harold Brown Chair in Defense Studies at CSIS, is the former commander United States Strategic Command (STRATCOM), and 8th Vice-Chairman of the Joint Chiefs of Staff. He discusses disruptive potential of hypersonic technology and weapons with Touraj Riazi of the NATO Association of Canada.
What destabilizing consequences will hypersonic technology have on global strategic stability?
The definition of destabilizing is when one group generates a capability (advantage) that its adversary does not have (disadvantage). There are two options to restore your advantage – either invest in that technology or an alternative to it, or attempt to take advantage of your adversary before they field that new capability. Hypersonic technology creates that instability and forces a choice.
Generally, there are two means by which survivability and maneuverability are acquired. The primary method for years has been speed. Stealth is a recent alternative. For instance, I have a better chance of surviving and accomplishing my mission if I am moving at a speed that is faster than your ability to maneuver when reacting to me. I also have a better chance of accomplishing the mission if my adversary does not know where I am. Hypersonics represents a return to focusing on speed as an attribute of survivability; but, this shift away from stealth does not mean its total disposal.
It is in this area where hypersonic technology imposes costs on an adversary. If I’m inventing hypersonic capabilities to use against an adversary, they are forced to react and try to offset that. They will certainly be behind, and frankly, there is a premium price to pay in catching up. This is destabilizing for a period of time – although stability eventually resumes, and this imbalance is neutralized. The question then becomes how much will be invested in this technology and how long will it benefit me?
Moore’s Law projects that 30% of the stealth technology on an airplane built today will have been superceded by new technology prior to the fielding of that plane. Therefore, 30% of the total investment is already gone. When the plane is fielded against a ‘near peer’, 100% of that technology will be neutralized. At best, that technology might produce benefits lasting 25 years against low-end opponents. The value of investing in hypersonic technology cannot truly be assessed without these calculations.
Looking at hypersonic technology requires making the distinction between three regimes of hypersonic speed: below Mach 5, Mach 5-10, and above 10. Pushing through the atmosphere at hypersonic speeds requires a lot of sustained energy, which is problematic because of fuel consumption. Travelling 1000 miles probably requires an aircraft the size of an F-16 just to carry the fuel for the engine.
What will the time difference equate to, if that 1000 miles is traversed at a speed of Mach 5 as opposed to Mach 1? It would only be a minute or two. Now the question becomes: what is my adversary unable to accomplish in a minute or two? The operational advantage is relatively small and will not be sustained; therefore, a minute or two would not likely justify such an investment.
However, investing in such a capability would impose costs on my adversary by creating a necessity to develop defensive weapons against an object moving at such speeds. However, there would not be a need to build a great number of them because I cannot afford to build that many weapons in the first place.
If, however, the speed is increased to Mach 20, and the distance to 10,000 miles, then the cost calculation would dramatically alter too because the primary unit of time would then become hours not minutes. This would enable me to be on one side of the country while the adversary thinks I am on the other side. This is really something different.
Most of the current work with hypersonics is taking place in the developmental phase to discover where leverage points exist and how they can be made useful. However, even though we are aware of an advantage a particular technology brings, there may be a need to shelve it because a necessary component of the technology has not yet matured. Today, some of the technology, such as the engine type technology, is starting to mature, while the heat management systems are a real problem for sustained inside-the-atmosphere operations. This again raises the question of whether there is sufficient technology to field a weapon now. If the answer is yes, how many will be built (due to the limited use and advantage)?
The concept of Prompt Global Strike (PGS) creates non-nuclear options. Does America’s willingness to limit a conflict to conventional forces mean an adversary would also refrain from escalating a conflict to the nuclear level?
A significant number of people concern themselves with the esoteric aspect of this equation – on the premise that if a warhead comes off a long-range missile, it must be carrying a nuclear payload. Therefore, it is assumed that an adversary will automatically react at the nuclear level. That is hardly the criterion a national leader will use in a response, because “going nuclear” will lay waste to the world.
In my opinion, nuclear weapons act more as a self-deterrent than as a means to deter an adversary. A leader will usually question why a nuclear weapon would be necessary to destroy the targets he or she wants to destroy. Eisenhower, when he established the post-WWII nuclear enterprise, separated nuclear weapons and nuclear forces from the rest of the force. What he really did, was separate the manufacture and sale of nuclear weapons from the people who purchase them and from those who use them. In other words, the Department of Defense (DOD) does not buy or make nuclear weapons, since that is someone else’s responsibility. DOD employs the weapons only. That separation of powers, so to speak, has been turned into a separation of forces. Consequently, there are general purpose and strategic forces that do not mix together. That is crazy, especially in deterrence theory. For example, no effective strategy would have a queen on the board but not use it, because it is so powerful.
Integrating STRATCOM into the broader strategy ensured that deterrence is a component of diplomacy from the first encounter with the adversary. Between diplomacy and total destruction of your adversary, are questions that need to be asked to avoid mutual destruction.
The first is how to integrate all those pieces. And then, what are your counter escalatory strategies, and how will they be employed? The difference between striking an ambiguous target and a certain target needs to be examined. If, for instance, a certain building is considered a strategic target, it is a fact that the building will not walk away. Knowing where the building is permits you to destroy it with a 1000-pound bomb instead of a nuclear device.
Some would argue for using a nuclear weapon in this scenario because they want to “impose great penalty.” However, we must recognize that we all live with that penalty because only so many of these weapons can go off before the earth goes cold. This also calls into question the necessity of arsenals containing 30 or 40 thousand nuclear weapons when a lot less is needed to completely disrupt the planet.
This reality makes one think more responsibly at the presidential level of decision-making. Options that the President and national command authority can entertain involve: a conventional choice; a general purpose choice; and a nuclear choice.
What is considered strategic is not the weapon but striking that building (the target). If a strategic target exists half way around the world that needs to be struck quickly, as Vice-Chairman, I probably do not want to force the president into using a nuclear weapon to do it. Previously, the only option a president had to strike a target on the other side of the earth in half an hour was using a nuclear weapon if he did not want to wait four days to respond. Now I have three different ways to hit that target today in an hour. That is Prompt Global Strike!
How dependent is a concept like Prompt Global Strike on radars and intelligence, and what vulnerabilities are created, considering that speed and accuracy need intelligence to be effective?
That question is asked by members of Congress who believe that if they are going to spend money on a weapons system, that system should be able to destroy all of the targets on that Congressman’s list. This is not true of any weapon. There is always a target set out there that you must address.
At the most nascent stage, it is possible to place a completely blind, dumb bomb precisely where it needs to be if it has a target set that is not moving, at least for the duration between the weapon launch and striking its target.
Let’s say there is a truck inside my CEP (Circular Error Probable) going 60 miles per hour. The CEP can be increased if the aperture of the sensor is opened up to at least 60 miles. Doing so allows me to find the truck without having to increase the yield or the explosive power of a weapon. However, consider trying to detect and strike an airplane that’s flying at 500 miles an hour. Since the aperture of my sensor cannot be opened that far, the plane is simply not going to be in my target set. So intelligence is required, but that is not the only aspect. What is really required, is a general area of activity that can be placed within a CEP. As long as that CEP is within the range of my onboard sensors, or the target is detected and unable to move, it can be struck. That alone is a sufficient target set to justify developing a system.
I would begin with a relatively small target set, and state that I can handle all buildings, all bridges, all highways, and all fixed targets – these can be explored with a terminal sensor. That terminal sensor will have at least one phenomenology, say its radar, that detects anything reflecting energy back inside of, for example, a 100-mile circle. Therein is the capability of the weapon to increase the target size and go after more targets.
When intelligence permits the tracking of a target that needs to be eliminated in only a general area, it might then become necessary, especially under time pressures, to increase the yield of a weapon to compensate for the lack of intelligence. What matters to the President is having that option, and that is exactly what PGS provides.
Touraj Riazi is a Research Analyst at the NATO Association of Canada.
This interview was published by the NATO Association of Canada: http://natoassociation.ca/interview-with-general-james-cartwright-pt-1-on-hypersonic-weapons/