Fwd: FW: (ai) Planning Air Operations: Lessons from OperationStrangle in the Korean War

[Ed Evanhoe <evanhoe@arbuckleonline.com>]

Thought this might be of interest.  Published in 1992

Ed


> Subject: Planning Air Operations: Lessons from Operation Strangle in the 
> Korean War
>
> source: 
> <http://www.airpower.maxwell.af.mil/airchronicles/apj/kirtland.html>http:// 
> www.airpower.maxwell.af.mil/airchronicles/apj/kirtland.html
>
>
>
> Published Airpower Journal - Summer 1992
> DISTRIBUTION A:
> Approved for public release; distribution is unlimited.
>
> Planning Air Operations:
> Lessons from Operation Strangle in the Korean War
> Lt Col Michael A. Kirtland, USAF
>
> OFTEN THE lessons we learn best from combat come not from our victories 
> but from our failures. Such a case is the Rail Interdiction Program, 
> better known as Operation Strangle, conducted in Korea from the summer of 
> 1951 to early 1952. Enthusiasm for air power and the desire to show that 
> air power was enough to win a war were not enough to make up for 
> deficiencies in planning, command structure, or resources that plagued 
> this operation. The lessons those airmen learned so painfully, and at such 
> a cost, forty years ago are still relevant today. Effective air operations 
> come from understanding one's doctrine, knowing one's limitations, and 
> most of all, from thoroughly planning the campaign from beginning to end.
>
> The Korean War began with a surprise North Korean attack against the South 
> on 25 June 1950. The woefully unprepared and battered South Korean army 
> rapidly retreated. US military forces were introduced almost immediately 
> from Japan. Unfortunately, they had served since the end of World War II 
> as an army of occupation in Japan and were not ready for the difficult 
> combat they faced in Korea. By late summer of 1950, the 100,000-man 
> Republic of Korea (ROK) army had lost over half its strength. US forces 
> brought over piecemeal from Japan were sent directly into the fight and 
> did not fare much better. North Korean forces had reduced the ROK/US 
> control over the Korean Peninsula to a small area around the port of 
> Pusan--the now famous Pusan perimeter.1
>
> American air power, in the form of Far East Air Forces (FEAF) and Fifth 
> Air Force stationed in Korea, was not much better prepared for war. FEAF 
> planning for Korea consisted of assistance in the evacuation of Americans 
> in the event of war.2 But air power recovered much more quickly than did 
> the land forces, scoring its first aerial victories just two days after 
> the opening of hostilities.3 Air Force action quickly destroyed much of 
> the North Korean air force, reestablishing air superiority. FEAF's Bomber 
> Command began bombing missions over North Korea. Fifth Air Force fighters 
> supported land forces by attacking enemy formations on the ground. Between 
> Bomber Command raids, close air support by Fifth Air Force, and a truly 
> heroic stand by US Marines and Army units around Pusan, the enemy assault 
> was finally slowed long enough for United Nations (UN) forces and US 
> military reinforcements to arrive.
>
> Relief from the pressure on Pusan came in September when Gen Douglas 
> MacArthur launched a daring invasion at Inchon. Within a week, US forces 
> had broken the enemy lines around Pusan and linked up with units of X 
> Corps that had landed at Inchon. It was now the North Koreans' turn to 
> head into full retreat. By late October, UN forces had driven the enemy 
> back into North Korea, decimated his air and ground forces, and occupied 
> the North Korean capital at Pyongyang. By mid-November UN forces were 
> approaching the Chinese border along the Yalu River.4
>
> UN forces were again surprised on 26 November when 300,000 Communist 
> Chinese forces entered the war. UN forces began a continuous withdrawal 
> and retreat that lasted for the rest of 1950, finally halting some 70 
> miles south of Seoul.5 Once again it was American air power that slowed 
> the advance of Communist forces. The enemy attack bogged down under the 
> constant assault by air interdiction missions as well as close air support 
> by Fifth Air Force, Navy, and Marine forces. UN forces went on the 
> offensive in late winter and early spring of 1951, recapturing Seoul and 
> advancing northward.6 Finally, in the summer of 1951, armistice 
> negotiations began.
>
> With the coming of the truce negotiations, UN forces, under US Army 
> general Matthew B. Ridgway, wanted to keep pressure on the Communists in 
> order to encourage the negotiations process. However, the American Joint 
> Chiefs of Staff (JCS) wanted no operations that would either appear to be 
> offensive in nature or result in high casualties. This attitude was 
> reflected in a JCS message sent to Ridgway on 11 August 1951 that said, 
> "If Armistice discussions fail, it is of greatest importance that clear 
> responsibility for failure rest upon the Communists."7
>
> Air Force leaders, still wanting to show just what air power could achieve 
> in war, were quick to offer interdiction as the solution. Brig Gen Edward 
> J. Timberlake, Fifth Air Force vice commander and later acting commander, 
> suggested a road/truck interdiction effort, which was supported by FEAF 
> headquarters with a goal of paralyzing the Communist transportation system 
> between the 39th parallel and the front lines.8 The official objective of 
> Operation Strangle, according to FEAF, was to "interfere with and disrupt 
> the enemy's lines of communications to such an extent that he will be 
> unable to contain a determined offensive by friendly forces or be unable 
> to mount a sustained major offensive himself."9 According to noted air 
> power historian Robert F. Futrell, both the Air Force chief of staff, Gen 
> Hoyt S. Vandenberg, and FEAF commander, Gen Otto P. Weyland, had 
> misgivings about the operation under the conditions imposed by the JCS and 
> the truce negotiations.10 However, there is no indication that they 
> expressed those doubts at the time.
>
> General Weyland said the goal was to isolate the enemy, making him unable 
> to sustain his frontline forces, but then he waffled in this by adding 
> that a parallel objective was to "punish the enemy to the maximum extent 
> possible."11 Choosing the name Strangle for the initial road/truck 
> interdiction operation further confused the issue of just what the 
> objective was intended to be. Air Force leaders were looking for a strong 
> name for the operation and wanted to avoid using the term interdiction in 
> favor of terms that clearly indicated that this was an air campaign.12 
> Ground commanders seem to have chosen to interpret the term Strangle to 
> indicate that air interdiction would "strangle" the enemy by choking off 
> his supplies and preventing him from maintaining an army in the field. The 
> choice of the name Strangle itself has become a classic lesson in the 
> dangers of picking names for military operations (see sidebar). The 
> ultimate result was an unclear objective, loosely interpreted to suit the 
> goals and needs of various organizations, with no common understanding of 
> what it was supposed to achieve. The principle of the objective was 
> clearly violated. Because of this violation, only mixed results came from 
> the effort. The road/truck interdiction program was short-lived and not 
> very successful; it killed trucks without really achieving any strategic 
> objectives.13 Because of the problems with the road/truck interdiction 
> effort, Eighth Army and Fifth Air Force began a joint survey in July 1951 
> to consider potential weaknesses in the enemy logistical system. This 
> survey was to be the basis of planning for the Rail Interdiction Program, 
> also known as Operation Strangle, even though the survey was not completed 
> until more than a month after the program began. Unfortunately, another 
> important lesson flowed from failure. The development of a joint survey 
> was the correct action to take in planning an air campaign to support 
> Operation Strangle's perceived objectives. But surveys should be completed 
> and the right questions asked before the campaign begins. The joint study 
> focused on the logistics needs of the Communist field armies and 
> determined that the enemy required 2,400 tons of supplies daily to support 
> their combat forces. Further analysis indicated that while it would take 
> approximately 6,000 trucks to support this effort, 120 railcars could 
> carry the same load, making rail transport a more reasonable target for UN 
> air forces to attack. Three alternative solutions were postulated as 
> potential methods for attacking the rail transport system. Bridges could 
> be destroyed, rolling stock could be attacked, or the rail lines 
> themselves could be destroyed. Headquarters FEAF and Fifth Air Force 
> decided by process of elimination to attack the rail lines as the primary 
> target, reinforced by secondary attacks on the bridges, as well as 
> preplanned and target-of-opportunity attacks on rolling stock.14 Here 
> again, failure to follow through with proper analysis diluted the 
> effective planning that had previously been done.
>
> The major effort to analyze the enemy logistical system was a textbook 
> example of how to determine a center of gravity for enemy activity. Rail 
> transport was indeed essential to the enemy effort in the field. In fact, 
> Lt Gen Nam Il, the chief Communist delegate to the peace negotiations, 
> speaking of the overall air effort during the Korean War, attributed the 
> success of the UN forces to their bombing campaigns.15 But at the same 
> time, the analysis failed to consider just how successful interdiction 
> could be in defeating the North Korean rail supply effort. Little 
> consideration was given to the notion that interdiction is most effective 
> when combined with a ground campaign which causes the enemy to exhaust his 
> supplies at a rate that cannot be sustained.
>
> The most successful period for Operation Strangle was the first three 
> months of the campaign, when Eighth Army was still conducting ground 
> operations to consolidate and secure its positions. By the autumn of 1951, 
> when ground activity decreased, so did the effectiveness of the 
> interdiction effort. While the study had determined the level of supply 
> effort needed by the enemy when engaged in battle, little consideration 
> had been given to what level of supply was required to sustain the enemy 
> in static defensive positions when neither side was conducting offensive 
> operations. Still less effort was given to considering if the rail 
> interdiction efforts of Operation Strangle could reduce the enemy supplies 
> reaching the front to a level below that needed to sustain a static 
> defense. Air planners and air commanders had simply assumed through their 
> beliefs in air power that they could interdict the enemy supply levels to 
> the point where the enemy would be forced to negotiate a settlement 
> rapidly and in good faith.
>
> In its official pre-Rail Interdiction Program estimate of 14 August 1951, 
> Fifth Air Force stated that it, FEAF Bomber Command, and naval Task Force 
> 77 together "have the capacity of destroying the enemy's rail system in 
> North Korea and of hindering his highway transportation system to such an 
> extent that he will not be capable of opposing the US Eighth Army 
> effectively."16 In November, when General Vandenberg received an update 
> briefing at Fifth Air Force headquarters, the assumption that rail traffic 
> could be reduced to near zero was still held: "Our plan is to reduce the 
> lines to such a state of unserviceability that we can keep them blocked 
> with a minimum of effort."17 This estimate was given despite the fact that 
> at the time a maximum effort was not achieving the same objective.
>
> The difficulty of cutting rail traffic was not fully considered. Planners 
> simply asserted that air attacks could make sufficient cuts in rail lines 
> to stem the flow of supplies. This assumption ignored the recent 
> experiences of IX Tactical Air Command (TAC) rail interdiction efforts in 
> World War II, which showed that cutting rail lines was extremely difficult 
> and that, until a new munition was developed, this was not a particularly 
> effective technique when compared with the effort involved in achieving 
> those cuts.18 The failure to follow through with the analysis process to 
> determine if effective means of interdicting the rail supply effort below 
> acceptable levels for the enemy was a major defect in the planning effort. 
> Planners asked the right questions when they determined rail transport as 
> a center of gravity. But they neglected to ask the logical follow-up 
> questions to determine if the center of gravity could successfully be 
> defeated with the means at hand. During its most successful period, 
> Operation Strangle decreased enemy rail transport to between 4 or 5 
> percent of its prewar levels. However, that 4 or 5 percent, combined with 
> other methods of transport, was sufficient to support the needs of the 
> Communist forces in a static defensive position.19
>
> In fact, making cuts in rail lines was extremely difficult. Only one out 
> of every four sorties flown actually produced a rail cut. With a typical 
> sortie carrying two 500-pound bombs, the statistical results showed only 
> 12.9 percent of the ordnance dropped had any effect on the rail system.20 
> As Operation Strangle entered the Korean winter, the results were even 
> worse. Bombs often simply skipped off the frozen ground and exploded 
> harmlessly, littering the countryside with shrapnel but not cutting the 
> rail lines. In addition, by this time Communist forces had begun to react 
> to UN air attacks, decreasing the effect of successful bombing missions 
> and increasing the danger to UN flyers.
>
> Not accounting for enemy reaction to Operation Strangle was another key 
> lapse in the planning proccess. Initially, the interdiction effort had 
> been successful, destroying enemy supplies faster than they could be 
> replaced. Combined with Eighth Army ground activity, the rail interdiction 
> effort was hurting the enemy. There were even reports of food shortages in 
> some areas. Realizing the need to maintain their supply lines, the 
> Communists cannibalized existing double-track rail lines in order to 
> assure that at least a single-track rail line would remain open. In many 
> cases, trains were shuttled the short distances between rail cuts and the 
> cargo unloaded and transferred to another existing rail line in order to 
> complete the journey to the front. By October 1951, it seemed as if the 
> rail interdiction effort would prove successful. But the enemy was 
> beginning to overcome the difficulties created by the interdiction effort 
> and FEAF proved slow to react to enemy tactical changes, signaling the 
> eventual downfall of Operation Strangle.
>
> The first enemy reaction was to increase the air defense pressure on FEAF 
> Bomber Command attacks on the bridge system. The slow-moving B-29s were 
> extremely vulnerable to MiG activity, and with only a limited number of 
> B-29s available, high loss rates could not be tolerated. Communist air 
> attacks against Bomber Command formations intensified until restrictions 
> were placed on how far north they could operate.
>
> The enemy proved extremely capable as well in the area of deception 
> techniques, creating the impression of destroyed bridges and rail lines 
> when, in fact, the bridges or rail sections were in good working order. 
> Bypass bridges were rapidly constructed, in some cases even before the 
> original bridge was destroyed. In addition, some bridges had removable 
> sections so that they appeared to be destroyed by day but were fully 
> functional for nightly rail traffic.21 A poor understanding of deception 
> techniques was a serious weakness in FEAF intelligence and photo analysis 
> efforts. It resulted in a failure to strike numerous targets that should 
> have been hit and allowed the enemy to successfully move his supplies 
> while the UN forces believed they had stemmed that movement.
>
> The enemy proved to be willing to commit a vast amount of human resources 
> to the effort of keeping rail lines open. Manpower, in the form of 
> enforced Korean and Chinese labor, was a virtually unlimited resource that 
> could be stationed at close intervals along the rail lines. When rail cuts 
> were made, they could be repaired in very short periods of time, often in 
> no more than six to eight hours and sometimes less.22 The tools and 
> supplies required were simple, plentiful, and inexpensive. The end result 
> was that, typically, a rail line that was cut by air attacks was back in 
> operation by the next day and had to be continually restruck to keep it 
> shut down. The cost to the UN forces in materiel resources was far greater 
> than to the enemy. This same lack of understanding of what reliance on 
> human labor and simple tools could accomplish would haunt US forces again 
> during the Vietnam War. Being technologically oriented, the US 
> military--and perhaps especially the Air Force--gave short shrift to 
> nontechnical solutions to military problems.
>
> Another way Communist forces used their vast manpower resources to good 
> advantage was the simple expedient of human transportation. An April 1952 
> study of enemy reactions to the Rail Interdiction Program showed, for 
> example, that 100 men transporting mortar shells on their backs could meet 
> the enemy's daily requirement for mortar shells for an indefinite length 
> of time. By combining those supplies reaching the front by rail, truck, 
> and foot, Communist forces were not only meeting their needs, they were 
> actually able to stockpile some supplies for future use.23 In spite of a 
> maximum, sustained effort by air forces, interdiction alone could not meet 
> the objectives set for Operation Strangle. Lack of analysis combined with 
> enemy ingenuity and perseverance to stifle the air interdiction effort. 
> The enemy understood their logistical problems far better than UN analysts 
> did. By using the blinders of Western thinking to view possible solutions 
> to the problems of logistical support while under air attack, UN forces 
> ignored the possibility of simple, but labor-intensive, alternatives.
>
> The most critical enemy reaction to the interdiction effort was the 
> movement of antiaircraft assets to protect the rail network. FEAF viewed 
> this as proof that the Communists needed the rail system and that the air 
> attacks were hurting them. In this assessment they may have been correct. 
> But the enemy's ability to sustain attacks was significantly greater than 
> FEAF's ability to sustain the increasingly greater losses of aircraft and 
> personnel in making those attacks. Fifth Air Force units were assigned 
> specific sections of rail lines to attack. Because the same sections of 
> railway were attacked day after day, often in the same sequence of 
> sections and at the same time of day, the Communists could concentrate 
> automatic weapons fire and antiaircraft artillery (AAA) along the rail 
> line to provide the best air defense.24 Because of the concentrated AAA 
> fire, bombs had to be dropped from higher altitudes, decreasing their 
> acuracy. In addition, a larger percentage of the sorties had to be devoted 
> to suppression of enemy air defenses, further decreasing the effectiveness 
> of attempts to cut the rail network.
>
> In the end, the cost became prohibitive for UN air resources. In the 
> seven-month period from the start of the Rail Interdiction Program until 
> mid-March 1952, 243 aircraft were lost on interdiction missions and 
> another 290 suffered major damage. The cost in human terms was 245 airmen 
> killed or missing and 34 wounded. The loss rate was double the replacement 
> rate for aircraft, four times the rate when seriously damaged aircraft are 
> included.25 Obviously, this kind of negative exchange rate could not be 
> sustained. The cost was simply too great, especially when compared to the 
> damage being inflicted on the enemy.
>
> Failure to account for enemy reaction to air attacks and failure to 
> adequately adjust tactics to deal with enemy reactions proved to be 
> another costly error for Operation Strangle. Originally designed to last 
> 45 days, the campaign was continuously extended as it struggled to meet 
> its ill-defined objectives. UN military planners saw no obvious 
> alternative course of action to achieve the objectives either of 
> "strangling" enemy logistics or of pressuring the enemy to negotiate in 
> good faith. So the Rail Interdiction Program was simply extended. 
> Continuing the campaign long beyond its intended length without careful 
> consideration of the costs only further separated Operation Strangle from 
> its originally envisioned objectives, no matter which definition of the 
> objectives was used. By December 1951, Fifth Air Force had concluded that 
> Operation Strangle was not working, but General Ridgway insisted it should 
> be continued.26
>
> That General Ridgway should insist on continuing an air operation that his 
> air component considered futile further points out a problem in the air 
> campaign planning process used in Korea. General Ridgway inherited the 
> Korean command structure from General MacArthur, albeit with some 
> modifications. It remained throughout the war an Army command structure 
> masquerading as a unified command system. But it was never a truly unified 
> command structure with equivalent-level component commanders, each 
> representing and controlling his own area of expertise. This was 
> especially true for air activity. Even within the Air Force, no single 
> commander or staff organization had control over all air assets. Fifth Air 
> Force controlled fighter-bomber and light bomber assets, and FEAF Bomber 
> Command controlled B-29 attacks. Meanwhile, naval Task Force 77 controlled 
> naval air assets, and the 1st Marine Air Wing worked independently as 
> well. Eventually a geographical area of responsibility agreement was 
> worked out giving Marine, Navy, and Air Force units separate areas of 
> operations.27 The beginnings of the route pack system used in Vietnam can 
> be seen in these service-oriented geographical arrangements.There was no 
> air component commander and little or no coordination between the 
> services, significantly diminishing the overall effectiveness of air 
> operations.
>
> In the end, interdiction failed to achieve the results its early planners 
> had envisioned, and it became a matter of putting the best face on an 
> unsuccessful operation. General Ridgway told the JCS that air interdiction 
> had seriously affected enemy supply operations, diverted thousands of 
> troops, and destroyed thousands of trucks and rail cars.28 The Air Force 
> proudly cited the statistics showing the destruction they had wrought. But 
> the FEAF staff study that would end the Rail Interdiction Program 
> concluded that interdiction of rail lines was not worth the effort and 
> that--given the restrictions placed upon them in terms of unclear 
> objectives, lack of effective munitions, and geographical restrictions 
> along the northern border of Korea--air power could not be decisive in 
> Korea.29
>
> Failure to clearly state objectives after considering accepted doctrine, 
> and to thoroughly analyze enemy centers of gravity and the available means 
> of attacking those centers, had doomed Operation Strangle before the first 
> sortie ever left the ground. Lack of thorough planning and lack of a 
> unified command structure with control over all air assets had further 
> weakened the efforts of Operation Strangle. Attempting to simply extend a 
> short-term operation into a full aerial campaign would not suffice in 
> achieving the objectives. Slow reaction to enemy efforts to defeat 
> Operation Strangle depleted resources until it was finally admitted that 
> the effort was insufficient.
>
> Air interdiction had been successful in limited roles earlier in the 
> Korean War. But it must be remembered that those efforts were for a period 
> of limited duration and in coordinated effort with ground operations to 
> achieve maximum pressure on enemy resources. Planners of military 
> operations, especially air planners, should consider the legacy of 
> Operation Strangle before planning future air campaigns.
>
> Notes
> 1. Larry H. Addington, The Patterns of War Since the Eighteenth Century 
> (Bloomington, Ind.: Indiana University Press, 1984), 253-56.
>
> 2. Secretary of the Air Force, Office of Public Affairs, Korea: . . . The 
> Suspended War (Kelly AFB, Tex.: Office of Public Affairs, 1990), 1.
>
> 3. Ibid., 2. USAF fighters downed seven North Korean aircraft that day, 
> including the first kills by USAF jet aircraft.
>
> 4. Addington, 256-57.
>
> 5. Ibid., 257.
>
> 6. Ibid., 258.
>
> 7. Message, 98713, Joint Chiefs of Staff to CINCFE, 11 August 1951.
>
> 8. Robert F. Futrell, The United States Air Force in Korea, 1950-1953 (New 
> York: Duell, Sloan and Pearce, 1961), 296.
>
> 9. Robert F. Futrell, Air Operations in the Korean War, 1950-1953 
> (Washington, D.C.: USAF Historical Research Division Liaison Office, March 
> 1961), 25.
>
> 10. Futrell, USAF in Korea, 403.
>
> 11. Otto P. Weyland, "The Air Campaign in Korea," Air University Quarterly 
> Review 6, no. 3 (Fall 1953): 21.
>
> 12. History, Fifth Air Force, July-December 1951, appendix, "Notes on the 
> Use of the Term `Operation Strangle'," 2.
>
> 13. Col R. L. Randolph and Lt Col B. I. Mayo, The Application of FEAF 
> Effort in Korea, FEAF Deputy Commander for Operations, staff study, 12 
> April 1952, 5.
>
> 14. Futrell, USAF in Korea, 403-5.
>
> 15. Research Studies Institute, United States Air Force Operations in the 
> Korean Conflict, 1 November 1950-30 June 1952 (Maxwell AFB, Ala.: Air 
> University, 1955), 138 (hereafter cited as RSI study).
>
> 16. "The Story of `Operation Strangle'," Air Intelligence Digest, January 
> 1952, 7.
>
> 17. Ibid., 10.
>
> 18. RSI study, 138.
>
> 19. Futrell, USAF in Korea, 436.
>
> 20. Ibid., 409.
>
> 21. Maj Felix Kozaczka, "Enemy Bridging Techniques in Korea," Air 
> University Quarterly Review 5, no. 4 (Winter 1952-1953): 59.
>
> 22. RSI study, 150.
>
> 23. Randolph and Mayo, 5.
>
> 24. Futrell, USAF in Korea, 408.
>
> 25. Randolph and Mayo, 3.
>
> 26. Futrell, Air Operations in Korea, 26.
>
> 27. Futrell, USAF in Korea, 296.
>
> 28. RSI study, 152.
>
> 29. Randolph and Mayo, 14.
>
>
> --------------------------------------------------------------------------- 
> -----
>
> Contributor
>
> Lt Col Michael A. Kirtland (BA, Coe College; MPA, University of Colorado) 
> is a military doctrine analyst at the Airpower Research Institute, Center 
> for Aerospace Doctrine, Research, and Education, Maxwell AFB, Alabama. He 
> was a member of the initial cadre in the development and deployment of 
> ground launch cruise missiles, serving at the training squadron and as 
> chief of training at Florennes, Belgium. He served as a military studies 
> instructor at the US Air Force Academy and as a Titan II missile launch 
> officer. He was the first associate editor of the Airpower Journal and 
> haas published in numerous military publications. He complied and edited 
> the Air University Review Index and is currently completing the editing of 
> the five-year index of Airpower Journal. Colonel Kirtland is a graduate of 
> Squadron Officer School, Air Command and Staff College, Air War College, 
> and the National Security Management Program.
>
> Disclaimer
>
> 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.
Ed Evanhoe, PO Box 916, Antlers, OK, 74523-0916
Life Member: Special Forces & Special Operations Associations
Author:  DARKMOON:  Eighth Army Special Operations in the Korean War