The continental air defense mission evolved during the Cold War to detect and intercept Soviet bombers attacking North America via the North Pole. The continental air defense force that carries out that mission is within the North American Aerospace Defense Command
(NORAD), which is a joint US and Canadian command. A growing USSR long-range bomber threat encouraged Canada and the US to expand their defense cooperation with agreements to build extensive radar lines such as the Distant Early Warning (DEW), mid-Canada, and Pinetree radar systems. These were deployed in the 1950s. In August 1957, Canadian and US officials announced the establishment of an integrated command in Colorado Springs which would centralize operational control of continental air defense. On 12 September 1957, NORAD Headquarters operations commenced at Ent Air Force Base, Colorado Springs, Colorado. On 12 May 1958, the Canadian and US governments formally exchanged diplomatic notes which constituted the NORAD Agreement. This agreement sanctioned the shared air defense command arrangements, under which the US benefits from the ability to receive early warning information from radars along Canada's northern tier. This improves the capability to provide timely warning for air launched cruise missile attacks and to initiate defensive measures.
Although the agreement initially called for a binational command structure for a fighter defense against long-range Soviet bombers, the nuclear tipped intercontinental ballistic missile soon emerged as the primary threat to the North American continent. Thus, NORAD's primary emphasis shifted during the 1960s from purely air defense, to warning and characterization of nuclear attack by manned bombers and ballistic missiles. This led NORAD leaders to develop and acquire sophisticated land-based missile warning networks, as well as space-based warning capabilities, and to build the extensive command and control system of Cheyenne Mountain Complex.
In 1982 Defense Secretary Weinberger provided Congress the Air Defense Master Plan, which laid out the strategy for countering the growing Soviet strategic threat. The plan outlines a far forward perimeter defense of North America that can detect, intercept, identify and negate air-launched cruise missile [ALCM] equipped bomber aircraft before they launch their missiles. Since then, the United States and Canada have invested heavily in a number of programs that will improve our ability to provide timely and reliable tactical warning, attack assessment, and damage limitation to North America.
Investments in the Over-the-Horizon Backscatter Radar Sys tem [OTH-B] and North Warning System [NWS] significantly improved air defense warning and assessment capability. Modern NWS radars replaced the obsolete Distant Early Warning [DEW] line radar. They have substantially better low altitude coverage than the DEW Line and were to complement the additional capability provided by the OTH-B radar system. Fifteen long-range NWS radars are now in operation across Canada and 39 short-range NWS radars were fielded. This improved capability to detect the airborne threat and direct modern, long-range, interceptor aircraft to their targets permited a better alignment of strategic defense force structure.
The nature of the evolving threat and the limited number of defensive forces dictated a perimeter defense. Extended-range cruise missiles can be launched well outside the boundaries historically established by strategic air defense forces around the CONUS. To defend the United States from this threat, the US must forward deploy interceptor aircraft and E-3 Airborne Warning and Control Systems [AWACS] aircraft to locations in northern Canada in periods of heightened tension. The changed threat rendered the previous line of 1950's technology aircraft control and warning radars obsolete. Therefore, the Canadian Air Defense Identification Zone [CADIZ] in southern Canada was deactivated by agreement between Canada and the United States on June 30, 1988 and its associated line of radars was closed.
Starting in 1989, NORAD began participation in the counterdrug efforts of the US and Canadian governments, as a direct application of the command's air sovereignty mission. NORAD major responses to the unfolding security needs of the 1990s: include: instituting a flexible alert policy; consolidating air defense sectors and modernization of command, control, and communications systems, shifting the US air defense fighter force provider to the Air National Guard; refocusing of counterdrug activities; reinvigorating planning for defense against cruise missiles; assessing the role of ballistic missile defense as part of NORAD operations; and expanding interfaces with space system capabilities for warning and defense.
NORAD consists of a binational headquarters at Peterson Air Force Base, Colorado Springs, Colorado, and the three subordinate Regions of Alaska, Canada and the Continental US. The Canadian and Continental US regions are further subdivided into sectors. The Regions and their subordinate Sectors receive information from a surveillance network of ground-based radars augmented by airborne radars. Selected US Federal Aviation Administration (FAA) and Transport Canada(TC) joint-use radars also feed into the network. Although the NORAD Regions send summaries of important radar data to the combined NORAD/United States Space Command (USSPACECOM) Command Center in the Cheyenne Mountain Complex in Colorado Springs, the NORAD Regions use the majority of the radar data to accomplish the aerospace control mission at the Regional level. The Canada East and Canada West Sector Air Operations Centers (SAOCs) were consolidated at Canadian Forces Base North Bay in 1994, and the Canadian NORAD Region Headquarters is scheduled to move to Winnipeg in 1997 as part of the restructuring of Canada's operational air forces into a single operational headquarters. The Continental US NORAD Region merged the Southwest and Northwest SAOC at McChord AFB, Washington in 1995.
The requirement to forward deploy interceptors along the northern reaches of North America in time of crisis was consistent with the cruise missile and bomber threats. As such, there was no plan to relocate the 18 fighter aircraft and associated support from each of five squadron locations along the northern-tier. However, the military need to maintain 24-hour home-base alert using two fighter aircraft from each of five CONUS northern-tier units was no longer valid in light of the elimination of the supporting radar/CADIZ control system. Therefore, the US discontinued home-base alert at five northern-tier Air National Guard [ANG] bases, but relied on northern-tier units on detached alert to cover some of the peacetime alert requirements in support of the ADIZ along the eastern, western, and southern US borders. This shared the peacetime air sovereignty mission, allow each unit to maintain proficiency in this important part of the air defense operation, and maintain forward basing for northward deployment during periods of heightened tension.
This concept did not reduce ANG strategic air defense force structure. It did not deactivate any ANG interceptor squadron. It did not affect announced force structure modernization plans. Each squadron was modernized with F-16ADs on schedule. It did not alter the specific contributions to the air defense mission fulfilled by northern-tier ANG interceptor squadrons in support of NORAD's operational plans. Each squadron continued to conduct alert, but at a detached site. Each continued to train and exercise in preparation for both their peacetime and wartime taskings. This recognized the evolving threat and the deletion of the supporting radar/CADIZ control system in southern Canada last year and advances to the logical next step of terminating peacetime air defense alert at these bases where there was no longer a valid military requirement.
The US force is currently comprised of 180 Air National Guard F-15A/B and F-16A/B aircraft located in 10 units and 14 alert sites in the United States. In addition to the 10 dedicated units, 2 F-15 dual-tasked general- purpose units stand alert for NORAD -- an active unit at Elmendorf, Alaska, and an Air National Guard unit at New Orleans, Louisiana -- part of which is on 24-hour alert. NORAD has initiated a flexible fighter alert concept. This concept allows NORAD Region Commanders to tailor their aerospace control forces and alert postures to meet the perceived threat within their specific areas of responsibility, reduce their overall level of effort and reduce expenditures to meet their fiscal goals. Surveillance of approaches to North America continues; however, intercepts are now based on regional activity and intelligence information.
Critical aspects of strategic air defense revolve around two basic assumptions. The first is that defense of North American airspace will continue to be a mission requirement. The second is that the threat against North America will remain significant in the future. The nature of the threats against North America has changed dramatically since the collapse of the Soviet Union. This threat evolving from the scenario of the mass attack to the lone drug smuggler in a small, low flying, slow aircraft. Only Russia has both the systems and platforms capable of placing a weapon within North America. However, more countries are expected to possess land attack cruise missiles in their inventories. These systems will become more sophisticated in the near-term before stabilizing over the next 10 to 15 years. It is possible that, given extensive marketing, very potent systems will be in the hands of third world nations not now considered a threat. To be effective against North America, cruise missiles require a "first stage carrier." Russia maintains a viable fleet of intercontinental bombers and submarines which are capable of carrying cruise missiles. Most other countries will need similar "first stage carriers" of some type for current design cruise missiles. The operational concept for strategic air defense is to maintain constant surveillance, warning, and attack capability for defense of the North American continent and maintenance of air sovereignty. The forces/systems must be sustained in order to maintain readiness and achieve victory. Readiness is maintained through exercise of the strategic air defense system 24 hours a day, 7 days a week. Additionally, both live and simulated exercises such as Amalgam Warrior and Vigilant Overview provide an arena for units to employ their skills and training against the threat.