Toward a Sustainable US Defense Posture: The recent evolution of US air attack capabilities

Carl Conetta. Project on Defense Alternatives Briefing Memo #42, 02 August 2007.

At the time of the 1991 Persian Gulf war, less than 8 percent of America’s combat aircraft – USAF, USN, and USMC – had the ability to deliver guided weapons autonomously. Since then, this capability has generalized throughout the combat air fleets, including large bombers. (The capacity of America’s fleet of 97 mission-authorized bombers to precision munitions makes it, in this regard, the equivalent of more than 7 wings of tactical aircraft.)

Although the Government Accountability Office (among others) have challenged the most ambitious claims made for precision-guided munitions (PGMs), a non-controversial conclusion is that they allow a five- to eight-fold reduction in bomb expenditure to achieve a target effect similar to that achieved by the best non-guided methods. (The advantage may be somewhat less for area targets.) Also contributing to increased combat capability since 1991 has been the generalization of night-fighting and all-weather capabilities throughout the combat air fleets and significant improvements in target acquisition and data fusion and sharing.

In light of the advances in US air attack capability, it is not surprising that the 2003 Iraq war involved only one-third as many combat aircraft sorties as its predecessor and less than nine percent as many air-delivered munitions. Notably: the proportion of air-delivered munitions that were precision-guided grew from 8 percent to 68 percent. The number of fighters and bombers deployed by the United States declined from approximately 1,100 for the 1991 Gulf War to 655 for the 2003 war. And deployed aircraft were worked much harder in 1991 than in 2003: about 1.3 sorties per day per plane versus 0.9.

Looking forward to 2010, the advances in US guided-weapon attack capability will continue as the combat air fleets add all-weather munitions of substantially longer range, smaller size, and greater accuracy with more numerous and “smarter” submunitions. Over the next five years we will see the introduction of (or more general use of) extended-range, jam-resistant JDAMs, the Sensor Fused Weapon, the Wind-Corrected Munitions Dispenser, Joint Air-to-Surface Stand-off Missiles, and the Low-Cost Autonomous Attack System. Perhaps most significant is the introduction of the GBU-39 Small Diameter Bomb (SDB) which, as noted by Defense Industry Daily, will “dramatically increase the strike capability of every combat aircraft in the US inventory.” Indeed, theoretically, the SDB will increase the PGM carrying capacity of America’s combat air fleets five-fold – from 8,000 weapons to 40,000.

In 2010, America’s combat aircraft will possess twenty times the interdiction capability — on average and unit for unit, as their 1990 counterparts. Currently planned US air forces will be smaller, however – resulting in an aggregate capability somewhat less than 15 times greater than in 1990.

By comparison, traditional conventional adversaries have not nearly kept pace with US developments. Already in 1997, the Defense Intelligence Agency had noted a 20 percent reduction in armor threats. More generally: the United States moved from spending only 80 percent as much on defense as its potential adversaries did in 1985 to spending 250 percent as much in 2001. Since then the gap has widened further. Today the United States accounts for more than 60 percent of all military modernization spending worldwide, while Russia and China, for instance, together account for less than ten percent.

The dramatic growth in the capability of US combat aircraft does not imply that a commensurate reduction in fleet size is advisable, however. Quantity of platforms remains an important factor in that flexibility increases with the size of air fleets and risk declines. The United States would not want to put its “eggs” in too few baskets. Still, some significant reduction from the presently planned fleet size is possible.

How much is enough? We can gain some insight from America’s recent wars. During the past 15 years, the United States deployed air armada’s of various sizes to fight its wars: 1,100 combat aircraft in 1991; 300 for Operation Allied Force (plus 200 allied); approximately 250 for Operation Enduring Freedom; and 655 for the main combat phase of Operation Enduring Freedom. The average number of combat sorties flown each day varied widely: 1,400 for Desert Storm, 140 for Allied Force, 82 per day for the first 78 days of Enduring Freedom, and 700 for Iraqi Freedom.

Given current capabilities and those new ones now emerging and being introduced, the United States might handle comparable contingencies with combat air packages comprising 200 to 500 fighters and bombers. With a future all-service force of 1,920 mission-assigned fighters and bombers, the United States could surge as many as 1,250 combat aircraft at one time – a sufficient number to handle multiple war and deterrence tasks.

Toward a Sustainable US Defense Posture: Rethinking the demand for aircraft carriers

Carl Conetta. Project on Defense Alternatives Briefing Memo #42, 02 August 2007.

Among US air power assets those that are carrier-based have a special role. Where access to land bases is limited, aircraft carriers can bring tactical air power within reach of enemy bastions. Together with other sea-based strike assets and long-range bombers, carriers can help overcome the anti-access challenge. But this fact should not exclude them from consideration for reduction. In fact, the United States has more of this asset than it reasonably requires. And, it is important to remember that sea-based air power is relatively vulnerable and expensive. Indeed, sortie for sortie, it costs more than twice as much as land-based tactical air – all things considered.

America’s requirement for big-deck aircraft carriers can be divided into a “surge” requirement for crisis response and a peacetime requirement for continuous forward presence. Relevant to the surge requirement is the actual experience of recent wars. Three or four aircraft carriers were directly engaged in Afghan operations at any one time during October-December 2001. During the first phase of the 2003 Iraq war, four or five were engaged. During the 1999 Kosovo war, one.

In none of these wars were the engaged carriers employed to their fullest, however. For instance, during the first month of Operation Iraqi Freedom, naval fighters flew an average of 0.8 sorties per day. They are capable of flying two, at least – and the Navy claims they can do more, in a pinch. Looking to the future: The target attack capability of each air wing will increase significantly with the addition of smaller, longer-range, and more accurate PGMs. In 2005 Senate testimony, then Chief of Naval Operations, Admiral Vernon Clark, asserted that the number of targets that a carrier air wing could attack per day would increase from 700 to more than 1,000 by 2010 – having already risen substantially from 200 in 1997. Implicit in this is the option to reduce the overall number of carriers and wings.

In its FY 2007 budget, the Navy asserts that, given an 11 carrier fleet, it can surge six carriers for war within 30 days and another within the next 60 days. This, as a result of its new Fleet Response Plan (FRP). This implies an emergency or “surge” utilization rate of 63 percent. A somewhat higher rate could be achieved through changes in homeporting arrangements, rotations of crews, further reorganization of maintenance schedules, and reduced utilization of carriers for simple presence missions. Some reform along these lines would allow a 9-carrier, 8-wing fleet to surge “five plus one” for crisis response. In 2010, these six carriers, fully utilized and equipped with weapons now being fielded or procured, should be able to strike well over twice as many targets per day as the five that deployed for Operation Iraqi Freedom.

Supplementing the future offshore strike capability of US carriers would be the long-range attack capability of America’s bomber force – able in the future to carry five times as many PGMs as today (on average). Also supplementing carrier power would be the rest of the Navy’s surface fleet and the four Trident submarines that have been reconfigured for conventional missions. The surface fleet is equipped with approximately 8,000 Vertical Launch Systems, which can fire Tomahawk missiles – as can the Tridents. The Navy is building its stock of conventional land-attack Tomahawks up towards a total of 6,000 or so. (Approximately 800 were used in Operation Iraqi Freedom.) Finally, the Navy will have mini-carriers to call on as well, once the new class of LHA(R) amphibious assault ships are commissioned. Among other aircraft, these will carry 20 F-35s.
With only eight active and one reserve big-deck carriers in the fleet, the Navy would not be able to keep more than 2.5 of them continuously “on station” during peacetime – even given recent FRP innovations. However, homeporting one more overseas would increase this number, as would a crew rotation scheme. At any rate, peacetime naval presence abroad need not center on aircraft carriers. This much is recognized in the Navy’s new Global Concept of Operations, which allows for greater flexibility in assembling naval groups. Today, these include not only Carrier Battle Groups but also Expeditionary Strike Groups (built around amphibious assault ships), Surface Strike Groups (built around surface combatants), and independent operations by the Trident cruise-missile subs. These smaller, more varied, and more numerous groups allow for greater flexibility and more thorough coverage.