Air defense is the most problematic element of the War on Terror. One of the major questions surrounding the 9/11 attacks (and one of the seeds of many paranoid conspiracy theories)  is, where were the defenses? It took nearly three hours for U.S. air assets to respond to  the attacks, to the grave puzzlement of many taxpayers, who believed that at least some of the Defense Department's multitrillion—dollar purse must have been applied to direct defense of the country. They were unaware — and would have been shocked to learn — that on 9/11, the United States possessed virtually no air defenses to speak of.

Some years ago I managed an office in Clifton, New Jersey, about fifteen miles west of Manhattan. A few blocks away stood a building ( memory fails me here, though I seem to recall it being a recruiting center) which featured as a lawn ornament a very long, very thin, and very white missile. It was, in fact, a Nike Ajax, and the building had once been a Nike site, one of several surrounding Manhattan. For years that missile had stood ready for launch in case of attack against the New York metropolitan area. Now it lay on its side, warhead long disposed of, engine stripped, little more than a hollow shell.

On 9/11, one of my first thoughts was, 'If that missile had been on a launch rack, things would have turned out very differently.'

That remains true today. Despite the fact that the sole successful mass terror attack against the U.S. was carried out by air, no effort has made to upgrade or bolster national air defenses. Airliners are viewed — very much mistakenly — as being the sole threat, countered only by the TSA's absurd and ill—designed airport gauntlets. That, for all practical purposes, is the sum total of U.S. air defense. Apart from Air National Guard units placed on alert around major metropolitan centers, the U.S. remains as undefended as it was before 9/11.

A little history: the eyes

It wasn't always this way. After the USSR tested its first A—bomb in 1949, the U.S. began strenuous and far—ranging programs to provide a layered air defense of the continental United States. (True to form, the country had neglected air defenses in the immediate postwar period. The sole assets were propeller—driven fighters flown by, you guessed it, the Air National Guard.)

The first step was comprehensive radar system covering all threatened approaches. The  country's northern tier soon had full coverage. This was supplemented by the Pine Tree Line, a series of microwave detectors strung across the Canadian wilderness. Theses detectors could not track an aircraft, but would sound an alert if anything passed overhead.

Finally came the DEW (Distant Early Warning) Line, a system of radar stations just south  of the Arctic Circle stretching from Alaska to Greenland. Dozens of these stations, the sensitive radar antennas protected by huge geodesic domes, were built across the remote north under extremely trying conditions in one of the most impressive construction efforts on record.

(It was one of many such projects during the 1950s, including the Interstate Highway System, the Strategic Air Command's 2,000—aircraft bomber—tanker fleet, the Navy's atomic submarine fleet, and the first steps toward an ICBM force and a submarine—launched Polaris missile fleet. If any single one of these projects were to be proposed today, the response would be instantaneous cries of 'We can't afford it', and 'We don't have the resources'. Don't even think about the environmental impact statements and hearings that would be required everywhere across the country.)

Coastal radar coverage was provided at first by airborne platforms, using both aircraft and blimps, and later by the 'Texas Towers', radar stations patterned after offshore oil rigs and placed at the very limits of the continental shelf. In the early 60s, the system was supplemented by the BMEWS (Ballistic Missile Early Warning System) network, a northern—based network designed to track hostile missile launches.

The aircraft

Now we could see them coming. Catching them was another matter. It required the USAF  nearly a decade to procure suitable long—range interceptors capable of engaging attacking  bombers with some promise of success. The interim saw a series of the most problematic, not to mention plain evil, aircraft ever to enter the U.S. inventory. The F—89 Scorpion was the first, known to pilots as the 'Flying Locomotive', a fighter so heavy it took half an hour to reach operating altitude  (you needed a very early warning with this airplane.)

It was joined by the F—94 Starfire, the final modification of the F—80, the pioneer U.S. jet fighter. Nicknamed the 'Slug', it was one of the first jets fitted with an afterburner. Not all the bugs had been teased out yet, and the F—94 became notorious for engine flameouts, in which the pilot would repeatedly attempt to restart the engine until left with no choice but to eject (along with his radar officer), leaving the F—94 to make a large, unsightly hole in the ground.

The last of this group was the F—102 Dagger, the first attempt at an supersonic interceptor. Testing revealed that the F—102 could scarcely get out of its own way. Further research discovered that smooth transonic flight required a certain ratio between fuselage and wings (the 'area—rule principle' to get technical). The F—102 was redesigned with a 'wasp—waist', a pinch at the rear of the delta wing, a solution that resulted in an aircraft so fragile and sensitive that a full quarter of the thousand—plane production run crashed. In little more than a decade the USAF had dumped most of its F—102s on the Air National Guard, where, at the hands of pilots like George W. Bush, it continued building on its reputation as a widowmaker. (What's that? Dan Rather didn't tell you this, you say? Hmm... I wonder why?)

It was the end of the decade before the USAF procured capable aircraft in the form of the  F—101B, a modified version of a sturdy escort fighter, and the F—106 Dart. The F—106 was a complete reworking of the F—102 concept, and a truly remarkable aircraft. It could be flown to its target from the ground, utilizing an early data—exchange system known as SAGE (Semi—Automatic Ground Environment). All the pilot had to do was fire the missiles.

The results

By the early 60s, the Air Defense Command (ADC) was defending the U.S. from air bases  across the northern tier, equipped with nearly two thousand jets on full alert 24 hours a day. We're told by historian Walter Boyne that the peculiar demands of their mission — constant alert status at isolated bases in areas snowed in from October to March — created an insular culture among ADC pilots, who were considered odd by the rest of the Air Force.

Whatever the case, they did the job. The Soviets had fallen well behind in bomber development, badly fumbling the introduction of jets. The sole operational long—range bomber capable of reaching the U.S. with a worthwhile load was the Tupolev Tu—95 Bear, powered by turboprops, a step in  bomber evolution that the U.S. had skipped completely. The propeller—driven Bear was no match for U.S. defenses.

If any did slip through, they would be met by yet another line of defense, the Nike SAM  system. Nike Ajax was the first of the series, with development beginning at the end of WW II. Over 200 batteries were operated around the country beginning in 1956. The Ajax had a range of 25—30 miles and could hit targets flying up to 70,000 ft.

The Nike Hercules was a dramatic improvement, with an upgraded guidance system, improved range, and either a high—explosive or low—yield nuclear warhead. Range was up to 75 miles with a ceiling of 150,000 ft. The Hercules entered service in 1958, eventually arming 145 batteries, 110 of them converted Ajax batteries. The crews were housed in ordinary suburban homes, working in shifts on the same alert schedule as ADC. It must have raised quite a few eyebrows when the missiles down the street began rising on their launchers during exercises.

So by the early 60s, the U.S. was protected by a defensive system consisting of a complete  radar network. (The Soviets were not to match U.S. coverage until the mid—70s. Huge gaps existed across Siberia for most of the Cold War.) America was protected by a fleet of supersonic interceptors on constant alert and a final layer of well—tested SAMs. Such a system was not perfect, and might not have stopped every last attacker, but it was impressive enough to make an aggressor think twice. As the basis for further development, the system was unparalleled.

If work had continued with even a fraction of the effort put in during the 50s, constant improvement would have rendered it nearly impregnable.

Dismantling our defense

Instead, by the late 70s, the entire structure had effectively vanished, the bases closed, the  airplanes scrapped, the missiles trashed, except for those retained for display purposes. All that remained were the radars, still searching the northern skies for signs of an impending strike about which nothing at all could be done. It was, as more than one observer pointed out, the greatest unilateral disarmament recorded in history.

The reason was a thesis known as Mutual Assured Destruction, widely recognized by the  acronym MAD. Nuclear strategy had been long debated by such figures as Albert Wohlstetter, Henry Kissinger, and Herman
Kahn.The  argument revolved around Wohlstetter's concept of 'the balance of terror', based on the premise that nuclear weapons were so throughly destructive that simple knowledge that the other side possessed them was enough to discourage their use. MAD was the final refinement of this thesis.

According to MAD, defenses were in and of themselves destabilizing, endangering the balance of terror by deluding one side or the other into thinking it could survive an attack. From this point of view, possessing no defenses whatsoever was the safest possible stance, since it revealed to an enemy that you were not expecting to survive an attack and would never initiate one, therefore discouraging him from striking in the first place.

The McNamara factor

This elaborate calculus was adapted by defense secretary Robert S. McNamara, a cold individual with a hatred of the military, an obsession with figures, and a trail of serious failures behind him (he had been largely responsible for the marketing of the Edsel, for decades the byword for American commercial hubris and a synonym for a misconceived failed product).

McNamara was as interested in humiliating the generals and cutting the military budget as he was in securing the country's safety. MAD appeared to fulfill all those conditions equally. Within a few years MAD had become the de facto defense policy of the U.S., with little in the way of public debate. Current defenses were allowed to slide, with no effort made to replace them.

Mesmerized by the unfolding disaster of Vietnam (yet another McNamara project), the country paid no attention to the fact that it was being subject to a strategic experiment with effectively infinite levels of risk. Ground between Vietnam on one hand and his flagging plan for a national welfare state, the 'Great Society', on the other, President Lyndon B. Johnson allowed McNamara to go his own way. No other Secretary of Defense, and few cabinet members of any portfolio, ever acted with such autonomy, or did such damage in the process.

The MAD doctrine became subject to public examination only once, in a debate late in the  decade over a national Anti—Ballistic Missile (ABM) system. The ABM, first proposed as Nike X, then Nike Zeus, and at last Spartan—Sprint, was designed to defend against missile attacks, and represented a serious contradiction to MAD doctrine. McNamara handled the challenge the same way he had the Edsel as vice—president of Ford —— publicly acquiescing while privately sabotaging the program. The ABM system limped along for several years at the cost of billions until it was at last shut down as a consequence of the ABM treaty, without ever quite becoming operational.

The same fate overtook the existing defense network. Aircraft reached the end of their  service lives and were not replaced. The Nike Ajax was pulled out of service, leaving only Nike Hercules sites still active. Year by year, the country was being effectively disarmed without anyone noticing the fact.

Jimmy Carter

The end came in 1978. Jimmy Carter shut down the skeletal ADC (renamed the  Aerospace Defense Command, illustrating the rule that grandiosity is the herald of extinction). He had been personally assured by Leonid Brezhnev that the Soviet Union would never  attack the U.S. by air. (The USSR had never bought into the MAD thesis, and along with an impressive air—defense system, had fielded several jet—powered strategic bombers.)

The Nike  Hercules came to the end of its string the same year. The Air National Guard took over air defense duties on a part—time basis. And that was how it stood through the 80s, and 90s, and that is how it stands today. Five years after 9/11, not a single aircraft has been added to the inventory and not a single SAM system has been emplaced (the National Missile Defense system is, of course, quite another story).

No effort has been made to meet what in military terms is known as the 'air—breathing threat'.

The threat now

The consensus appears to be that the 9/11 attacks were a one—off, a plan that cannot be repeated. Any second attempt would be stymied by vigilant airport screening, with the unspoken assumption that passengers acting in the heroic mold of Flight 93 would serve as a backstop. Not a particularly compelling plan, on the face of it. Its failings were underlined this October 1st, when a Turkish Airlines 737 was hijacked by a lone unarmed man and forced to fly to Italy. If newspaper accounts are to be trusted, not a single finger was raised to stop him. At least in Europe, the 'lessons of 9/11" are in the process of being forgotten.

Apart from that threat, we also have freight airlines such as Federal Express, UPS or DHL, which have their own unique set of vulnerabilities. Corporate jets present an even more enticing target. We also have the air forces of advanced Muslim countries, along with their national airlines, both of which are vulnerable to Jihadi activities. (On Halloween 1999 an Egyptair 767 plunged into the Atlantic, killing all 217 people aboard. According the National Transportation and Safety Board report, the crash was due to 'the relief first officer's flight control inputs'. In plain language, the relief  pilot dived the plane into the sea, screaming 'Allahu akbar' all the way down.)

But if I were a  clever, ambitious Jihadi, I'd be thinking about cruise missiles.

Cruise missiles are widely considered to be advanced weapons systems, well beyond the  reach of terrorists. And that's true of enough of weapons such as the USAF's AGM —86B and the U.S. Navy's Tomahawk. 

But it's not true of the cruise missile in general, which can be considered the poor man's strategic weapon. The very first cruise missile, the Kettering Aerial Torpedo, which flew in 1919, was guided by a simple clockwork mechanism that sent the missile into a dive as it reached its target. Test flights carried out under the direction of aviation pioneer Hap Arnold, who later commanded U.S. air forces in WW II, were quite successful.

The first operational cruise missile, the German V—1, was scarcely more complex. A timer mechanism, calibrated for the distance between the launch site and the Greater London area, shut down the engine and flipped the missile over above the target area. British intelligence used this element to cripple many German strikes. The famed Double Cross spy system, which had 'turned' virtually every Axis agent in the UK, informed the Germans that the V—1s were overshooting the city. The Germans obligingly adjusted the timers, causing many V—1s to explode in empty fields in the countryside.

Far more advanced electronic systems, using inertial, radar and GPS technology, are available to terrorists from many vendors. It would be necessary only to adapt them. There are many remote aircraft designs available in kit form, some of them rather large. These could serve as a basis for a weapon capable of carrying out a biological or nerve gas attack against a large metropolitan area. Larger aircraft of the general aviation type (Cessnas and Pipers) could also be adapted to such a mission. It would require expertise and experience, but both can be gained over time. (Interestingly, a New Zealand hobbyist is involved in creating his own cruise missile to act as a warning of how easily it can be done.)

Launchings could be made from shipboard, Canadian woodlands, or even the U.S.  interior. A simple timer could release nerve gas or anthrax spores over the target. It's possible, under current circumstances, for such an attack to take place with no one being aware of it until it was over. Properly executed, such a strike would not cost the Jihadis a single man, leaving them free to carry out further attacks at their convenience. (An overlooked factor in the dearth of attacks since 9/11 is that Al—Queda expended all of its capable men in one strike — a serious drawback in suicide attacks, never to be overcome.)

Whatever the means, there remains without question a terrorist air threat, one that will grow more serious as time passes and technology grows simpler and more easily acquired, and the Jihadis become more experienced. One thing we can be certain of is that MAD will not work with terrorists.

What do we do?

Rebuilding the original air defense system is feasible both economically and  technologically, though rendered unlikely due to lack of political will. But maintaining the current status quo is out of the question. Air National Guard pilots are dedicated and usually have long experience, but there's a limit to what even the best part—time pilots can do.

The aircraft are also problematic. The F—15 and F—16 are unmatched as swing—role fighter—bombers, but are not quite suited to the all—weather interceptor role, which requires long range, a lengthy loitering time, a powerful radar, and a pile of air—to—air missiles. The F—14 Tomcat, just recently retired from operations, is the closest thing available. It was built to fly long patrols in protection of vulnerable fleet units. But it's also a difficult and expensive aircraft to keep in flight.

No new aircraft can be expected, nor would such a program be advisable, considering the  long lead time — often up to twenty years —— required for a new military design. The alternative is to modify a current model to fill the role. This is exactly what was done with F—101B Voodoo in the mid—50s after the initial failure of the F—102. Already equipped with adequate missile armament, the Voodoo was fitted with a powerful radar and a second seat for the radar operator. As is often the case, this modification on the wing was a success, with the Voodoo serving as a first—line interceptor for over twenty years.

The obvious candidate for such a conversion is the F—15 Eagle. The F—15 is almost the aircraft we need — it has the speed, the armament, and, with conformal fuel tanks, the range. With state—of—the—art electronics, a new interceptor version could easily do the job. At least some F—15s are due to be replaced by the incoming F—22 Raptor. Some consideration ought to be given to refurbishing and upgrading these aircraft to long—rang interceptor status.

The new interceptors could be based, not necessarily at Air Force bases, but at regional airports scattered around the country, much as the Air National Guard is today. Like the old ADC, these units would be on 24—hour alert. Pilots and aircrew would live in the community, and have no other duties other than air defense. Such a system would also have the benefit of increasing interaction between the citizenry and the military, which has faltered drastically since the last round of base closings.

As for direct city defenses, a successor to the mighty Nike Hercules is unlikely and unneeded. Even the most basic current mobile SAM system is more capable than the Nike family. Properly placed, a handful of  Patriot Pac—2 batteries could easily protect the New York metropolitan area. The only challenge would be adequate early warning.

It has been suggested that Aegis—class ships tie up semi—permanently at seaport cities to provide air defense (it has also been pointed out that if the Staten Island homeport had gone forward, an Aegis vessel  might well have been present on 9/11), but such warships have other duties. A better solution would be to set up Aegis—type radars onshore with datalinks to separate missile batteries, either Standards or Patriots. A single radar station could cover several cities, with perhaps three or four on the East Coast, one or two on the Gulf and four on the Pacific coast. Such a project would be expensive, but nowhere near as much as an attack of the magnitude of 9/11.

Farther down the line is the possibility of automating the entire system. The F—22 may well  turn out to be the last manned fighter plane. It's an open secret, not often spoken of, that the fighter drones are coming. Exercises carried out as long ago as the mid—70s clearly demonstrated that unmanned drones are superior in the dogfighting role, easily outmaneuvering the leading fighter of the time, the F—4 Phantom. Since this superiority is based on the physical limitations of the pilot, no conceivable advances could eliminate it.

Continental air defense is a perfect role for armed drones. Small aircraft with large wingspans (perhaps even swing—wings like the F—111 and B—1 to provide dash capability) could patrol large areas for periods that pilot fatigue currently renders impossible. Such fighters could be directed from either AWACs or ground stations, with monitors or even virtual—reality helmets providing operators with a clear view. On interception, the operators could examine any suspect aircraft, and either escort them in or, if necessary, attack with Sidewinder or AMRAAM missiles.

Energy weapons raise another possibility. The YAL—1A, a 747 modified to carry a chemical laser and related targeting electronics, has been under development since 1996. Originally scheduled to enter service in 2008, it's currently undergoing an upgrade that will undoubtably push back the debut date. Although designed to engage short—range ballistic missiles, there's no inherent reason why it can't be used against cruise missiles and related targets. Seven AL—1s are proposed, to protect U.S. overseas forces from attack. Doubling that number would provide a defensive umbrella for the U.S. Aircraft could fly regular patrols off the coasts, with flight plans prearranged so that laser coverage of each aircraft would slightly overlap.

An interesting variant of this idea involves lighter—than—air craft. Blimps were used in the early years in the early—warning role, with the large radar antenna fitted inside the balloon. A number of proposals for both blimps and rigid airships have been made in recent years (in fact, claims have been made that some have gone into production as 'black' projects), held back only by the lack of a compelling mission for such craft. The air—defense role could provide exactly such a mission. Large aircraft patrols are limited by both fuel consumption and pilot fatigue. Neither is a factor with lighter—than—air craft.

Many of the proposed designs are enormous, and could carry much larger loads than a 747, including AWACs—class radar systems and extra chemical 'ammunition' for laser shots — the AL—1 is limited to twenty shots before it must refuel. Enhanced performance of modern airships — many are designed to cruise in the low stratosphere — would enable them to avoid the most serious threat to airships operating in North America, the squall lines that regularly roll out of the Midwest. (Older airships were unable to either dodge or overfly squall lines. Both the Macon and Shenandoah fell victim to such storm systems.) Along with their air—defense role, such airships could at the same time carry out missions such as drug interdiction, weather observation, and general coast guard duties.

The prospect of airships calls to mind an even hazier vision. Airship designers have proposed  models able to operate for years without coming down. This leads to the possibility of the high—altitude aerostat, an enormous airship using jet engines to fill hot—air cells that would float semi—permanently in the lower stratosphere. Such a structure could lift hundreds of tons, allowing tracking and targeting systems of unparalleled power along with weapons that would dwarf those of the AL—1 aircraft. As few as two of these structures (they're probably best thought of as floating stations; they certainly can't be called 'aircraft') could cover each coast. They would be capable of defending not only against cruise missiles and aircraft, but also most types of ballistic missiles as well.

They would be visible from manyt parts of the country, brightly lit at night, glowing against the background of sunset and dawn. They would be seen by millions, who would know without doubt that they were well defended, and that the threats of the past retained no power over them.

But that's a program for later in the century. For the moment, it's enough to know that alternatives are available, that we don't need to mark time utterly unprotected as we have for  thirty years and more. We built a world—class defensive network when the United States was a much poorer and less advanced nation than it is today. We need to repeat the effort.

There's one thing we can be sure of: if we leave a single window open, the Jihadis will come through it. And beyond them loom the threats of a militant Iran, an expansionist China, a resurgent Russia.
 
There is nothing in the world more expensive than a cheap defense. We learned that on 9/11. We have no need of learning it again.

J.R. Dunn is a frequent contributor to American Thinker.