Military

The Effects Of Restrictive Rules Of  Engagement On The Rolling Thunder

Air Campaign

 

CSC 1995

 

SUBJECT AREA - Aviation

 

 

 

                               EXECUTIVE SUMMARY

 

Title:        The Effects of Restrictive ROEs on the Rolling Thunder Air Campaign

 

Author:       Major Matthew J. Dorschel, United States Air Force

 

Thesis:       The ROEs that were in place for the Rolling Thunder air campaign were

 

overly restrictive and made the conduct of the air campaign inefficient and hampered its

 

effectiveness.

 

Background:   The air war over North Vietnam has been at the center of many heated

 

debates on the proper application of air power and how it should be used and controlled.

 

Rolling Thunder provides an excellent example of how difficult the task of planning and

 

executing a successful air campaign is. Restrictive rules of engagement were put in place

 

for Rolling Thunder chiefly due to the fear of escalation and direct involvement of the

 

Soviet Union or China in the war. The goals of the air campaign were limited and

 

President Johnson hoped to achieve results through tightly controlled, applied pressure on

 

the N. Vietnamese government. The controls however, violated accepted air doctrine and

 

tied the hands of the military commanders that were tasked to meet the arduous objectives

 

of the campaign. Rolling Thunder barely achieved any of the desired results -- restrictive

 

rules of engagement undoubtedly played a major part in the failure of U.S air power in this

 

singular black mark on the record of American military aviation.

 

 

 

Recommendation:   US leaders must evaluate national objectives in future wars and decide

 

if they can be met with military means. Then, rules of engagement must allow those tasked

 

to accomplish the mission, to do so in a way consistent with proven doctrine and strategy.

 

As Desert Storm illustrated, airpower can achieve decisive results without restrictive rules

 

of engagement.

 

 

INTRODUCTION

 

 

   United States air commanders possessed superior numbers of aircraft and a more

 

capable air force than did North Vietnamese commanders during the air war in Southeast

 

Asia. Then why did they experience such poor results? Specifically, why was the famous

 

Rolling Thunder air campaign unable to achieve decisive results that might have positively

 

influenced the outcome of the war in Vietnam? The overly restrictive rules of engagement

 

(ROE), which put limits on where aircraft could fly, which targets they could attack, and

 

how they may attack those targets, were a significant reason that American air

 

commanders were unable to execute a successful campaign in Southeast Asia.

 

   The restrictive ROEs in Vietnam were put in place by President Johnson to ensure the

 

war did not escalate (Johnson feared Chinese and Soviet intervention). The President

 

hoped to achieve results by using an "air pressure campaign" to coerce the North

 

Vietnamese to discontinue supporting the Vietcong (VC). These restrictions violated Air

 

Force doctrine and tied the hands of air commanders that were tasked with the execution

 

of the air war in Southeast Asia.

 

   Many airmen who flew during the Vietnam War believe that victory would have been

 

possible for the United States had there been less restrictive ROEs. That assertion may no

 

be entirely true; certainly there are multiple causes for the failures of U.S. air power in the

 

Vietnam conflict; however, it is apparent that overly restrictive ROEs will have a dramatic

 

negative affect on the outcome of any air campaign.

 

   In all likelihood, America's involvement in future conflicts will be "limited" and

 

political concerns will be similar to those that were important during the Vietnam War. As

 

military leaders we must do what we can to ensure that ROEs will enable us to accomplish

 

favorable results, not keep us from achieving our objectives. The lessons from Vietnam

 

and specifically from the Rolling Thunder campaign have shaped Air Force doctrine and

 

continue to influence the way airmen plan and execute an air campaign.

 

   U.S. involvement in Vietnam began as far back as 1954, but the "official" position until

 

late 1963 was that no combat missions were to be conducted. It was not until the Gulf of

 

Tonkin incident in August of 1964 that U.S. air strikes became more aggressive: "On 4

 

August, North Vietnamese torpedo boats attacked two U.S. destroyers in the Gulf of

 

Tonkin. President Johnson ordered air attacks on the North Vietnamese boat bases and

 

their supporting fuel storage facilities in reprisal."1 A substantial deployment of U.S.

 

aircraft began and further attacks on U.S. facilities led to stronger action than retaliatory

 

air strikes.

 

   In the spring of 1965 the inability of the South Vietnamese military to thwart the

 

Vietcong and what appeared to be a collapse of their government led American leaders to

 

the determination that a bombing campaign was needed. The campaign was to achieve the

 

following objectives: reduce the flow of men and material from North Vietnam to South

 

Vietnam, send a clear message to the North Vietnamese leaders that continued action

 

would exact a high price, and raise the morale of the South Vietnamese.2

 

   From March of 1965 to November of 1968, a limited air campaign aimed at these

 

objectives was run -- it was called Rolling Thunder. This strategic air interdiction

 

campaign was conducted with rules of engagement that covered all aspects of the

 

campaign, from planning to execution. The ROEs were so restrictive that it was all but

 

impossible to achieve the desired results; they forced commanders and planners to go

 

against the central principles of Air Force bombing doctrine.

 

   The ROEs in place for the air campaign over North Vietnam included restrictions on

 

where aircraft could fly, what conditions aircraft could attack enemy forces (when they

 

were considered hostile), and what degree of force could be used both in self-defense and

 

attack.3 Another part of the ROEs restricted pilots from attacking certain types of targets

 

that were off limits; some of these were: enemy airfields, SAM sites, power plants, naval

 

craft in some areas, a 30 mile area around Hanoi, and a 10 mile area around Haiphong.4

 

The inability to attack certain targets made it difficult to stop the flow of men and material

 

into South Vietnam, and the requirements to spare North Vietnamese civilians limited the

 

use of certain types of munitions, such as B-52s and napalm. Until early 1967, in many

 

instances U.S. pilots were not allowed to engage enemy fighters unless they themselves

 

had been attacked first.

 

   According to the 1964 Air Force Manual I-I, Aerospace Doctrine, United States Air

 

Force Basic Doctrine, the goal of strategic interdiction was to reduce enemy logistical

 

support to levels below that necessary to sustain combat operations and to use the

 

principles of surprise and mass to attack those targets vital to enemy war-fighting

 

capability. By not following these proven principles of war, the air commanders were

 

unable to wage an effective air campaign and Rolling Thunder lacked the impact that was

 

necessary for achieving the stated political and military objectives.

 

Rolling Thunder ROE: -- Violation of Doctrine

 

   Restrictive ROEs not only made it difficult to damage the most important targets in

 

North Vietnam, they had an equally negative affect on the commanders and aircrews that

 

were tasked to plan and fight with the tight restrictions. Civilian leaders believed that the

 

restrictions were necessary to keep the war limited and achieve the objectives of reducing

 

the supply flow and sending a clear message to North Vietnam leaders; they imposed the

 

restrictions hoping that the threat of future destruction would force North Vietnam to the

 

negotiation table.5 This philosophy was not embraced by military planners and aircrews

 

who felt it was in violation of their training and contrary to Air Force doctrine.

 

   U.S. Military planners and airmen realized that the limited style of warfare they were

 

fighting was not producing the needed results. Air commanders proposed a set of tasks

 

that was designed to achieve decisive results and reduce the war-making capability of

 

North Vietnam. They wanted to disrupt external assistance being provided to North

 

Vietnam and impede the flow of supplies into the south, and directly attack the resources,

 

facilities, and operations in North Vietnam which were contributing the most to the

 

enemy's war effort.6 However, civilian leaders were not convinced and the ROEs that

 

protected these targets were kept while weak blows to the North Vietnamese periphery

 

continued. The fear inside the beltway was that a more efficient air campaign would risk

 

unacceptable civilian losses and collateral damage.

 

   The disagreement between the military and civilian leaders continued throughout the

 

Vietnam War, partly due to a mistrust that civilian leaders had for military leaders.

 

The president and his advisors often disregarded the advice of military experts, believing

 

that: "Generals know only two words: spend and bomb."7 The often referred to Tuesday

 

lunches at the White House (where President Johnson did much of the planning and

 

targeting for the air campaign) did not even regularly include the chairman of the JCS until

 

late 1967.8

 

   Due to the lack of military expertise, the targeting and planning effort was weak and

 

very ineffective. There was never a lack of significant targets in North Vietnam, but

 

aircrews were forced to fly against seemingly insignificant targets and even re-attack

 

destroyed targets, while SAM sites and MiG airfields were off limits until 1967.9 The JCS

 

target list was virtually ignored and targets remained protected for almost all of the

 

Rolling Thunder campaign. Two of the most significant target areas on the list were

 

Hanoi and Haiphong; targets in these areas could only be attacked if approved by LBJ's

 

Tuesday lunch group. Often, these targets were approved for short periods or during

 

periods of poor weather, which made it difficult (if not impossible) to achieve any desired

 

effect.

 

   Secretary of Defense, Robert McNamara testified before Congress in 1967, in response

 

to the targeting questions and stated that the targets influencing operations in South

 

Vietnam were the roads and material moving over these roads. McNamara's testimony

 

was an attempt to explain U.S. policy; he insisted that other North Vietnam targets were

 

not fundamental to the operations in South Vietnam.10 Many military commanders

 

disagreed with this assessment to no avail, "the President and the Secretary of Defense

 

continued to make the final decisions on what targets were authorized, the size and

 

frequency of sorties, and in many instances even the tactics used by the American

 

pilots."11

 

   Another restriction that tied the hands of American military commanders was the ROE

 

that restricted the use of the B-52 in North Vietnam. This weapon had great range,

 

armament capacity, and it struck fear into the enemy like no other weapon; it was

 

extremely effective in South Vietnam. The B-52 was prohibited from extensive use in

 

Rolling Thunder because civilian authorities believed it would have signaled a higher level

 

of escalation, and that it might cause Chinese or Soviet intervention.12 This prohibitive

 

measure to maintain the limited objectives of the war denied air commander from using the

 

principal of mass, and forced them to fly multiple fighter sorties where one B-52 would

 

have accomplished the job more effectively.

 

   The crews that flew the aircraft found the ROEs not only overly restrictive but

 

extremely complicated, confusing, and difficult to learn and remember. The list of

 

restrictions and limitations was so long and changed so often that they were difficult to

 

comprehend on the ground, much less remember and keep straight while in a fast moving

 

combat situation.13 Crews depended on daily study and on radar controllers to keep them

 

from violations of the complex ROEs, and from flying where they might not be able to

 

defend even when fired on.

 

   Several incidents of ROE violations led to court-martial charges; one that led to

 

charges against the commander and the aircrew was the strafing of the Soviet ship

 

Turkestan in 1967 near Haiphong.14 Fear of ROE violations and the consequences of

 

them led to a dilemma; many aircrews felt as if they could not accomplish their mission

 

without either getting killed by the enemy or brought up on court-martial charges by their

 

own governrnent.15

 

   American air losses over North Vietnam rose continuously with over 500 aircraft lost

 

during 1966 and 1967. Crews began to see that it was highly unlikely they would survive

 

a 100-mission tour in Southeast Asia.16 Many of these losses resulted from restrictions

 

against attacking SAM sites or other significant targets in or around populated areas. The

 

ROE restrictions allowed the North Vietnamese to continuously build up their air defense

 

systems in the most critical areas of the region (with Hanoi being the most significant).

 

The combination of restrictive ROEs and the heavy enemy air defenses made the job of air

 

commanders and each aircrew member more difficult than it should have been.

 

 

 

North Vietnam Exploits U.S. ROE:

 

   The restrictive ROEs in North Vietnam aided the enemy by providing sanctuaries and

 

restricted areas where they had the space and time to build up their air defenses to engage

 

U.S. aircraft. The piecemeal approach to attacks in North Vietnam did not allow

 

concentrated bombing and actually strengthened the will of the North Vietnamese as

 

opposed to weakening it. American leaders made it clear in public statements that we had

 

no intention of destroying the government of North Vietnam; the leaders in North

 

Vietnam saw this as an opportunity to exploit an American weakness.17

 

   The most significant restricted areas that provided sanctuary were the 30 mile area

 

around Hanoi, the 10 mile area around Haiphong, and a 25 to 30 mile "buffer zone" along

 

the Chinese border. These sanctuaries prevented attacks against key targets in the north

 

without prior approval from Washington. The North Vietnamese took advantage of this

 

by offsetting the damage done by our aircraft in non-protected areas. Because Haiphong

 

Harbor was a safe port, they were able to ship up to 85% of their war goods by sea and

 

download them with impunity 24 hours a day at that location.18 These safe havens

 

allowed the enemy to stockpile war materials until they could be moved to the south. The

 

"buffer zone" along the Chinese border was thousands of square miles where the North

 

Vietnamese could store and transport materials with no fear of U.S. attack. This made

 

any attempts at reducing the ability of the enemy to sustain their combat operations almost

 

futile.

 

   The enemy also took advantage of the restrictions in areas where attacks might result

 

in civilian casualties. North Vietnamese put air defense systems and war materials in or

 

near populated areas to protect them. Because of improvements in air defense systems,

 

the enemy was able to effectively identify/target U.S. aircraft from these sanctuaries. Even

 

when U.S. intelligence showed these areas to be crowded with supplies (and a legitimate

 

target according to the laws of war), ROEs prevented our aircraft from hitting them.19

 

   When restrictions were lifted in some areas (1967) any collateral damage was used by

 

the enemy as a propaganda tool to charge the U.S. with indiscriminate bombing of

 

innocent people. Exaggerated reports of collateral damage were effective in destroying

 

the already decaying support for U.S. involvement in Vietnam.

 

   Because U.S. airmen were required to positively identify targets, they were normally

 

restricted to fly during the day and in periods of good weather. When the enemy realized

 

this they took advantage by concentrating forces and materials in protected areas during

 

the day, and moving at night or during periods of poor weather. They were able to do this

 

in part because of the relatively short distances between prohibited areas; large quantities

 

of rolling stock could be moved the short distances at night or in periods of lousy weather.

 

   Possibly the greatest advantage that restrictive ROEs gave the enemy was time. The

 

ability of the enemy to build up their air defenses was due in large part to the freedom of

 

movement they enjoyed in the havens protected by ROEs. The air defense system in

 

North Vietnam was almost non-existent in 1965, but by the end of 1967 it became one of

 

the most complete and sophisticated systems in the world. SAM sites increased from 15

 

in 1965 to 270 by 1968; missiles fired from these sites increase from 200 in 1965 to almost

 

3,500 in 1967. The number of AAA guns grew from 700 in 1965 to over 7,400 in spring

 

of 1968.20

 

   The predictable nature of the American offensive also gave a distinct advantage to the

 

enemy in Southeast Asia; because of restrictions on where aircraft could fly -- the North

 

Vietnamese knew our likely routes and concentrated their defenses is these areas. The

 

redundancy of the attacks allowed the enemy to predict with measured success what the

 

most likely targets were and when they would be hit.

 

 

 

The Bottom Line: Military Objectives

 

   The initial objectives of Rolling Thunder were to stop the flow of men and material

 

into South Vietnam, send a clear signal to the North Vietnamese leaders that continued

 

support of the Vietcong would exact a high price, and build up the morale of the South

 

Vietnamese. Although Rolling Thunder was effective in raising the morale of the South

 

Vietnamese, it only slowed the flow of men and materials into South Vietnam, and the

 

campaign had no noticeable effect on the support for the Vietcong from Hanoi.21

 

   The objective of stopping the flow of men and material into the south would have been

 

problematic regardless of restrictive ROEs. The enemy by nature could operate on very

 

limited supplies and was able to move these supplies in small amounts over difficult

 

terrain. The only way to completely halt the flow would have been total destruction of the

 

enemy regime or occupation of its territory. Restrictive ROEs did limit the amount of

 

bombing in North Vietnam, however, this alone was not enough to keep Rolling Thunder

 

from achieving the goal of interdicting their supply lines. The flow of men and supplies

 

continued to increase throughout the campaign: "In 1965 approximately 12,000 North

 

Vietnamese soldiers had infiltrated South Vietnam, but by 1968 over 300,000 North

 

Vietnamese troops had entered South Vietnam."22

 

   Even with these problems Rolling Thunder was able to destroy a fair amount of the

 

North Vietnamese infrastructure; according to reports the bombing destroyed 77 percent

 

of all ammo depots, 65 percent of fuel storage facilities, 59 percent of all power plants, 55

 

percent of major bridges, and 39 percent of railroad yards.23 However, this success was

 

not enough to keep North Vietnam from being able to withstand a long war against the

 

United States (both economically and politically).24

 

   A continuous flow of materials and a large, unoccupied labor force allowed the North

 

Vietnamese to withstand much of the destruction. Russia and China were able to supply

 

the enemy along routes that were protected by ROEs and to store and disperse the

 

supplies from ROE protected sanctuaries. Food and POL imports from outside sources

 

kept the North Vietnamese well supplied, and they were able to continue the guerrilla style

 

fight that was so effective.25 The large North Vietnamese labor force also did much to

 

offset the destruction that Rolling Thunder accomplished. This force (over 300,000) of

 

laborers was able to quickly repair the damage to major targets and almost nullify bombing