Air University Review, March-April 1978

Communications and Crisis Actions

Brig Gen Charles E. Williams, Jr., USAF (Ret)

Crisis situations generally do not attract the deep analysis that historians give to general wars. Nonetheless, crises can lead to serious conflict if not controlled or resolved promptly. They really deserve more attention. With the growth in number, power, and diversity of atomic weapons as well as the number of countries possessing them since World War II, the penalties for failing to control crisis situations could be unnacceptably severe. As study of the conventional wars and numerous crisis/contingency operations in the intervening 30 years illustrates the fragile border between crisis and general conflict.

The growing impact of world opinion, the change from a bipolar world to one of multipolitical orientation, and the ever more severe consequences of general war make it increasingly important that we be aware of potential trouble spots and handle crises with speed, precision, and good judgment. Commanders must have fast and secure reward reporting, accurate situation reports, tight reins on the use of force, and, when needed, the capability to apply the right amount of force at the right time. For vast areas like the Pacific, this calls for forward-based forces and in-being, highly active command and reporting channels.

As a general rule, fast-moving, event-driven crises place great stress on command, control, and communications systems. By and large, we have to go with resources on hand or available in theater within a matter of hours. The situation usually involves use of highly mobile forces that must be supported by easily transported communications equipment. Timely communications both for reporting and control are extremely important. Voice coordination and direction of tactical operations become paramount over record communications, although both are needed. The Southeast Asian crises of 1975 illustrate the point well.

The collapse of the South Vietnamese and Cambodian governments during the spring of 1975 involved Pacific Command (PACOM) in a series of joint crisis/contingency operations. Eagle Pull, Frequent Wind, and Mayaguez are familiar names, at least to those of us in the PACOM. The response from United States forces was superb. The evacuation of Phnom Penh (Eagle Pull) proved to be a dress rehearsal for the rapid planning and fast response demanded in the evacuation of Vietnam (Frequent Wind) and the Mayaguez rescue. Analysis of these operations reconfirms many of our earlier conclusions about the importance of flexible communications in support of crisis actions and provides some new insights.

For example, one of the most important lessons is to recognize the value of satellite communications as a flexible, high-quality communication medium. This is not a new lesson, for we here in PACOM have stated our communication requirements in these terms over the years. But these crises provided real world situations wherein satellites and transportable terminals proved indispensable.

Figure 1. Southeast Asian communications in early March 1975

Figure 1. Southeast Asian communications in early March 1975

Figure 1 shows the general communications backbone for Southeast Asia in early 1975. The bulk of our precrisis communications to Southeast Asia depended on the military undersea cable (Wet Wash) from San Miquel Bay, Philippines, to Nha Trang, Vietnam. * The only other entry points were in Thailand, through the military satelite terminal at Ramasun, another very important link to Nakhon Phanom, and a few leased channels** on the commercial Intelsat terminal at Si Racha. Onward connection to Vietnam was via the military undersea cable (439L) from Sattahip and multichannel radio (troposcatter or tropo)*** from Warin. Communication with Cambodia depended on a military troposcatter link from Long Binh, South Vietnam. (See Table I.)

*This does not include limited teletype communication via the Diplomatic Telecommunications System directly to the embassy in Saigon

** A channel refers to a signal narrow-band voice path (nominal 3 to 4 kilohertz of bandwidth). It may be used to carry several teletype or data signals instead of one voice signal.

***Troposcatter is a transmission technique that involves bouncing signals off the troposphere. Through use of large (60-120) foot "billboard" antennas, it is good for distances up to 600 miles. It was especially useful in Vietnam, where it was not feasible to have microwave relay towers every 20 miles.

The undersea cables to Thailand and Vietnam were clearly vulnerable to enemy interdiction, as can be seen from Figure 1. Enemy capture or sabotage of the Nha Trang cable head would cut communications between the Philippines and Southeast Asia. A similar loss at Vung Tau would sever the cable link with Thailand. This vulnerability was a matter of serious concern to Commander in Chief, Pacific (CINCPAC), hence the provision of satellite communications that bypassed the Republic of Vietnam. Even with our considerable investment in satellite communications, loss of Nha Trang would seriously cut communications to the Southeast Asian mainland. Further, loss of Vung Tau and cross border troposcatter sites at Monkey Mountain

(Da Nang) and Pleiku would virtually isolate South Vietnam by removing access to the Thailand satellite terminals. It was not. difficult to predict the effect on communications of a successful southward sweep by North Vietnamese forces.

Figure 2 portrays the actual advance and the date each major link was lost. Our primary concern around the tenth of March was to retain high-quality communications with the embassy in Saigon, the defense attaché office at Tan Son Nhut, and the embassy in Cambodia, where evacuation was already imminent. It was essential to preserve the troposcatter link between Long Binh (Saigon) and Phnom Penh until the Cambodian exit was completed. Through the dedicated efforts of U.S. Army communications personnel on the Long Binh end and at the Military Equipment Delivery Team, Cambodia (MEDTC), in Phnom Penh, this important channel remained operational until all U.S. personnel left the embassy in Cambodia on 11 April. With the loss. of terrestrial links to Saigon imminent, we put. a transportable satellite terminal

Figure 2. Southeast Asian communications events, 18 March-29 April 1975

Figure 2. Southeast Asian communications
events, 18 March-29 April 1975

(TSC-54) into Tan Son Nhut, and it provided effective communications support after these terrestrial links were lost.

Table I.
Sequence of crisis events
in Southeast Asia, 1975

13 March Ban Me Thuot fell.
16 March Lost Pleiku. Tropo link to Warin
out. Kontum lost.
25 March Fall of Hue.
26 March Loss of Chu Lai and Tam Ky.
28 March Monkey Mountain (Da Nang)
fell. Lost remaining tropo link
to Warin.
4 April Added 12 Defense Satellite
Communications Systems
(DSCS) and 6 Intelsat channels
to Thailand.
12 April Eagle Pull (evacuation of Phnom Penh).
28-30 April Frequent Wind (evacuation of Saigon).
12 May Hijacking of Mayaguez.
13 May Mayaguez anchored at Koh Tang.
15 May Koh Tang landing. Mayaguez recovered.

From the tactical commander's point of view, the most vital communications in all three operations were his tactical radio networks--ultra high frequency (UHF), very high frequency (VHF), and high frequency single sideband (HFSSB). Radio was our only means of linking the widespread air, naval, and ground forces involved in these three operations. In the main, tactical radio networks functioned as expected. There are, however, important lessons for the future.

Because of its range and flexibility, high frequency single sideband was the mainstay for tactical contact among distant forces and back to their immediate headquarters. In terms of reliability and capacity, it did not measure up. Inherent high frequency propagation anomalies (fading, skip, frequency interference, etc.) lower reliability below an acceptable level for fast-moving crisis situations. The HF frequency spectrum is highly overcrowded, producing mutual-user interference. Loss of signal even for short periods of time can impede timely coordination of forces. Further these propagation characteristics and the narrow bandwidth of the signals yield only marginal quality and capacity. This makes HFSSB unsuitable for high-level coordination and the transmission of high-speed data. Heavy reliance on HFSSB for teletype/data communications results in message backlogs during crises, especially in field tactical communications centers and on ships of the fleet. HFSSB is also strongly susceptible to hostile intercept and direction finding. The really frustrating fact here is that although the shortcomings of high frequency have been identified over many years of use in exercises and actual conflict, we are still having to rely on it for key command and control communications. With today's demands for high-speed, high-capacity communications, HF is at best a backup medium.

Further complications arise from the fact that some nets are UHF, some VHF, and others HFSSB. Of course such nets cannot interoperate without special interfacing equipment. Few of the tactical aircraft involved were equipped with each type of radio. The Marine landing team on Koh Tang during the Mayaguez recovery needed both UHF and VHF radios to contact supporting aircraft directly. The quantitative impact of such a lack of interoperability is difficult to measure; however, there is no question that it complicates tactical coordination among diverse force elements, hampers operational monitoring, and forces ground units and aircraft to cover multiple frequency bands.

VHF and UHF gave effective service. Limited to line-of-sight distances, they lack the range of HFSSB; but they compensate through better voice quality, greater bandwidth, and reliability. In Frequent Wind and Mayaguez, an improvised manual airborne radio relay effectively doubled UHF range, extending it to approximately 400 miles. This added range was extremely important because of the geographical spread of forces. Unfortunately, the relayed links were not secure and were severely limited in capacity, i.e., to the number of calls the pilot could relay by voice while flying the aircraft.

An old lesson learned again--it is essential to have direct communications between ground forces and supporting TACAIR. A new twist on another old lesson--the task force commander needs secure voice and data communications, not only with supporting/senior headquarters but probably extending up the unified command chain to the National Military Command Center/National Command Authority and, of course, downward to his own forces, however dispersed.

Mobility and flexibility are increasingly important characteristics for PACOM forces. For the future, our communications backbone must be as flexible as we can make it; we must avoid the rigidity that characterized communications into Vietnam. We must increase communications capacity to remote areas. In my view, this calls for more reliance on satellite communications and the provision of highly mobile/transportable terminals, switches, nodal technical control elements, and local distribution equipment.

Effective solutions to these problems call for better investment decisions, perhaps some compromises, and resource reallocations. Satellite communications offer an important means of providing the tactical user a high-quality alternative to HFSSB. Both commercial and military satellite communications can supply flexible, high-capacity alternatives to fixed undersea cables. Some corrective programs are under way, but they deserve stronger emphasis and acceleration We cannot continue our present policy of launching only a few satellites at widely spaced intervals. Failure of the double Defense Satellite Communications System II launch in May 1975 delayed our achieving adequate satellite capacity in orbit. Fortunately, our one double launch in 1977 was successful, but these two satellites only replaced the two orbited in 1973 and now ate essentially worn out.

Both UHF and super high frequency (SHF) satellite communications are scheduled for the fleet and SHF for the mobile ground forces. SHF satellite terminals for secure voice and data are needed now in tactical command and control aircraft as well as in some strategic airborne platforms Our FLTSAT/AFSAT program* will help, but it will not provide direct/flexible connectivity for joint force operations. Automatic, wideband, high-altitude airborne radio relay in tactical operations has been a recognized need for many years but continues to fall out in favor of higher priority programs. The Airborne Warning and Control System (AWACS) would have been extremely useful in these three crisis situations, especially if it had contained anon-board SHF satellite terminal with secure voice/data modems to link it to component, theater, and National Command Authorities through the Defense Satellite Communications System.

*FLTSAT/AFSAT combined formerly separate Navy and Air Force satellite programs into one program. The space vehicle provides two technically separate sections which require distinctly different earth terminal accessing equipment.

Certainly there can be no question of the need for assured communications to control our strategic nuclear forces. Emphasis on these communications is appropriate, but there must be stronger emphasis on crisis communications. If we can effectively detect, report, and control the smaller crises, there is a diminished likelihood for conflict to expand to a nuclear level. To that end, we need a thoroughly integrated, satellite-based3 high-capacity communications system with mobile/flexible terminals, secure voice/data conferencing, and flexibility to interoperate/interchange with commercial systems. (Flexibility to interoperate with commercial satellites would greatly increase redundancy and survivability.) The technology already exists. No new developments are required. Let's face the problem squarely and solve it, not study it for another ten years.

San Antonio, Texas


Brigadier General Charles E. Williams, Jr., (Ret), (M.S., George Washington University) worked in command and control communications and computer activities much of his military career. He was Director, communications and Data Processing (J-6), on the staff of the Commander in Chief, Pacific, when he retired on 1 March 1977. He has commanded operations in FEAF and Vietnam; filled command and staff positions in TAC related to operations, command and control, communications and electronics; and served as Vice Director, Joint Tactical Communications Office, Fort Monmouth, New Jersey. General Williams is a graduate of the Air Command and Staff College, U.S. Army Command and General Staff School, Air War College, and the National War College.


The conclusions and opinions expressed in this document are those of the author cultivated in the freedom of expression, academic environment of Air University. They do not reflect the official position of the U.S. Government, Department of Defense, the United States Air Force or the Air University.

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