R.J. Rummel—A Multi-faceted Scholar

Rudolph J. Rummel always published just as R.J. Rummel but was well known in the profession as Rudy. He was a man of many talents, and to some of his readers he may also have seemed to present many different faces. He came from a broken home, yet became a devoted husband and father. He had an extensive academic publication record, but he also wrote six novels. He was an academic loner, but acquired a wide following, which has continued to expand after he withdrew from the academic scene and promises to continue to grow even after his death.

The main aim of this book is to review his work and to assess the development of his views over the span of his career. At the same time, several contributors relate his academic and political views to his personal life story. The authors of this volume share the view that despite what quibbles or even quarrels they might have with some of his writings, Rummel stands as a very significant contributor to the empirical and theoretical study of human conflict. At the same time, he was an intensely political person who has influenced the moral compass of many scholars in the profession.

A Rummel Timeline
On two occasions, Rummel (1976bRummel ( , 1989 has provided autobiographical accounts. The story of his checkered childhood and youth emerges here, as well as in his daughter's recollections (Chap. 2) and Doug Bond's interview with him (Chap. 3). Here, he also talks at length about his shifting research interests and his increasing unease with socialist ideology. I will attempt a very broad periodization of Rummel's professional work.
From the start of his education, Rummel embraced mathematics-apparently, a youthful interest in science fiction influenced this choice. Indeed, his first academic work was heavily mathematical, with empirical studies of conflict and a major textbook on factor analysis (Rummel, 1970). But, as Richard Chadwick explains (Chap. 5), for Rummel factor analysis was not just a methodological tool but also a key part of a theoretical framework that came to be known as social field theory. While many other scholars adopted and elaborated empirical findings that emerged from these projects, in particular those relating to the relationship between internal and external conflict, few others attributed the same theoretical importance to factor analysis. Nevertheless, Rummel's reputation as a quantitative scholar of note grew rapidly in the scholarly community and in policy circles. He received extensive funding from the US Department of Defense, through the Advanced Research Projects Agency (ARPA), 2 which funded a number of conflict research projects in the 1960s and 1970s. Rummel's projects, in particular the large Dimensionality of Nations (DON) Project, also involved substantial data collection, and the data were used by a wide range of scholars.
A second phase of Rummel's work started when, according to his own recollections (Rummel, 1989: 314) he took a step back from data collection and hypothesis-testing to look at the broader theoretical preconditions and implications of his work. He started what he has called an 'intensive and extensive liberal self-education' in philosophy, history, and the social sciences. This eventually led to the massive oeuvre collectively titled Understanding Conflict and War, published in 2 From 1972From (and again in 1996 renamed the Defense Advanced Research Projects Agency (DARPA), cf. http://www.darpa.mil. The vast majority of ARPA-supported projects were technical and weapons-oriented. ARPA is probably best known for its development of the ARPANET, which eventually became the Internet.
five volumes between 1975 and 1981. The series title was apparently proposed by Sage, but in retrospect Rummel regretted agreeing to this series title, since it only really fit vol. 4 (War, Power, Peace, 1979). As James Lee Ray argues (Chap. 8), it is in many ways an overlooked classic. Rummel himself, while not expecting it to be a hit, was unprepared for its being so widely ignored. The sales were poor. Only a few years later, an article in Journal of Conflict Resolution (Rummel, 1983a) was to change the landscape dramatically. This article, along with a two-part article by Doyle (1983), launched the democratic peace on the mainstream agendas of peace research and international relations. A number of other scholars joined in, notably Bruce Russett and Zeev Maoz. 3 Rummel once again became a household name.
A few years later, the debate was extended to a broader liberal peace, involving the Kantian triangle of democracy, economic interdependence, and international organization. This line of investigation was initiated by Oneal, Oneal, Maoz & Russett (1996) and is primarily associated with Bruce Russett and John Oneal, in a series of frequently-cited articles and a book (Russett & Oneal, 2001). Rummel (1976a) had expressed skepticism about the peacebuilding effects of trade and international organizations (cf. Chap. 6). He did not enter the new debate about the liberal peace, which started after he had retired from the university and stopped publishing articles in academic journals. His 1983 article on the democratic peace-and indeed, in his four subsequent articles indexed by Web of Science between 1984 and 1986referred to libertarianism rather than democracy. The same is true of Understanding Conflict and War. Libertarian was defined along two dimensions, political (where, of course, democracy featured prominently) and economic. In his articles on libertarianism and international violence, the term democratic peace does not occur at all. In his later work, however, even as the attention of the field moved to broader aspects of the liberal peace, Rummel focused on democracy. On his website, 4 democratic peace is one of the main headlines. In some ways, his work can be seen as a precursor of the more recent discussion of the capitalist peace (cf. Weede in Chap. 7, Gartzke, 2007). But as far as I have been able to ascertain, Rummel himself never used the term capitalist peace, and his work was sometimes critical of unbridled capitalism or liberalism. 5 From 2009, his blog was labelled freedomist rather than libertarian. And his two final books were called The Blue Book of Freedom (2007) and Freedom 's Principles (2008).
Although Rummel's work on the democratic peace focused mainly on the interstate democratic peace, he also eventually concluded that 'democracies are most internally peaceful', that 'democracies don't murder their citizens', 6 and that democratic freedom promotes wealth and prosperity and prevents famines. 7 It was the latter point that was going to lead Rummel into a new phase of his work and another major series of books on what he came to call democide, a concept that was deliberately chosen to be wider than genocide and politicide. Separate volumes examined the Soviet Union (1990), China (1991), and Nazi Germany (1992), before he summed it all up in Death by Government (1994) and Statistics of Democide (1997). In Power Kills (1997), he tied together his work on democracy and the various kinds of human conflict. The subtitle of this book was Democracy as a Method of Nonviolence. It underscored Rummel's long-standing commitment to a less violent world, even though as Erica Chenoweth points out (Chap. 11) he never commented directly on non-violent action as a substitute for insurgency and war. Rummel  Cf. Rummel (1976d: Chap. 22, 1981. 6 Chapter headings in Rummel (1997). 7 Rummel (2007: Chap. 6).
One of his Ph.D. students nonetheless studied this topic in his dissertation, with the use of factor analysis! (Bond, 1988).
The work on democide is probably the aspect of Rummel's work that captures most attention now. It was also to be his last major research effort even though he continued to publish shorter articles, blog posts-and six novels, to which I return briefly later.
In this brief attempt at a periodization of Rummel's work, I have omitted a book that does not fall clearly into any of the major periods. This is his book on the nuclear arms race, discussed in this volume by Matthew Kroenig & Bardia Rahmani (Chap. 6). In Peace Endangered: Reality of Détente (1976a), Rummel critiqued détente, expressed skepticism about arms control, and called for a policy that would give the West a clear nuclear superiority over the Soviet Union. Published at a time when liberals were hopeful about détente and arms control, it created a significant distance between himself and scholars who might have been receptive to his message about freedom and peace. Instead, it probably reinforced the prejudice, still common in peace research, that talking about a democratic peace just meant rehashing old enemy images of 'us' and 'them' and familiar propaganda for 'the free world'. Richard Chadwick notes in an aside (Chap. 5, note 2) an estrangement between Rummel and himself. It dates to this period, though not exclusively to this issue. Intriguingly, Rummel relates (1989: 317f) that his hawkish message was not well received in the national security establishment either, which led to a cut-off of his long-term funding from DARPA.

The Lone Ranger
Rummel's extensive writings are listed in Chap. 13 of this book. His work is frequently cited, and remains influential nearly two decades after he withdrew from academic publishing. Figure 1.1 shows the number of citations to his articles indexed in Web of Science for the past fifty years. Using the Author file, the total number of citations to his articles as of mid-August 2016, was 797. The overall regression line is obviously positive. But we can spot three humps in the annual citation rate. The first (which peaks in 1972) relates to his early work on methods and on the relationship between internal and external conflict. The next hump peaks in 1997 and is probably linked to the democratic peace, although a more detailed analysis would be necessary to establish this conclusively. The final peak, which is also the peak for the whole time series, occurs in 2007, and includes citations to his work on democide. However, it is not the case that his earlier work remains uncited in later periods. In fact, his 1967 factor analysis article has been cited more than 20 times since 2010. Table 1.1 shows his most-cited articles. This table was compiled from the Cited authors file of Web of Science rather than from the Author file. A Basic search on Author yields lower numbers because it does not include periodicals not indexed by WoS in that year (such as the European Journal of International Relations before 1997) and because a number of citations are not correctly linked to the relevant article. The discrepancies between the numbers derived from the Author and Cited author files are larger for the earlier years, when citation data were hand-coded from the print journals, apparently with little if any proofreading. Table 1.1 underlines the wide impact of Rummel's work on factor analysis as well as the importance of Journal of Conflict Resolution throughout his career. Half the top-cited articles appeared in that journal. The close personal relationship between Rummel and Bruce Russett is only partly relevant here, since two of the top articles were published before Russett took over as editor of JCR in 1972. In turn, Rummel's authorship was probably important to the reputation of the journal, too. All the five Rummel articles listed here were among the top five  (2016). All rights reserved. For a description of the limitations of this file to assess the total citations of an author, see below in the main text. Apart from a brief comment (Rummel, 2004a, b) the last WoS-indexed article by Rummel appeared in print in 1997 Understanding factor analysis, JCR (1967)  228  2 Dimensions of conflict behavior within and between nations, GSY (1963) 205 3 Libertarianism and international violence, JCR (1983) 202 4 Democracy, power, genocide, and mass murder, JCR (1995) 87 5 Democracies ARE less warlike than other regimes, EJIR (1995  75  6 Dimensions of conflict behavior within nations, 1946-59, JCR (1966)  72  7 Libertarian propositions on violence within and between nations …, JCR (1985) 69 8 Afield theory of social action with application to conflict …, GSY (1965) 61 9 How multinationals analyze political risk (with DA Heenan), HBR ( Research (1966Research ( , 1967Research ( , 1994 were among those that fell just short of the top-ten list. Another article close to the top ten was on the DON project in Comparing Nations (1969), a volume edited by Richard Merritt & Stein Rokkan (Rummel, 1966) articles in terms of citations in their respective volumes-the 1967 and 1983 articles were in first place, by a wide margin.
For the next generation of quantitative social scientists, the number of article citations is the most important indicator of academic success. Rummel was a more traditional scholar who published much of his most significant work in books. His somewhat contrarian stance may have caused him some trouble with journal editors and referees. In his autobiographical article (Rummel, 1989: 317), he hints at getting a number of rejections for articles dealing with the topics discussed in his book Peace Endangered (1976a). His books did not always travel a simple road to publication either, but nine books found a home at Sage (until 1981) and six with Transaction (from 1990). Table 1.2 lists citations to his most-frequently cited books, once again compiled from the Cited author file of Web of Science.
This list also underlines the wide impact of his work on factor analysis (as Ray suggests in Chap. 8). His factor analysis book was featured as a 'citation classic' in Current Contents (Rummel, 1987b). His more recent work on democide is also widely cited and has maintained high visibility in the current debate about the waning of war and violence. For instance, in his widely-cited book on the decline of violence, Pinker (2011) makes extensive use of Rummel's work on democide. Rummel's magnum opus Understanding Conflict and War is not as widely cited as one might expect. Because the books tend to be cited by the series title rather than by the volume title, I have not attempted to provide individual citation data for the five volumes. The importance of Rummel's books is also made clear by the fact that he has five times as many citations as Cited author than as Author, whereas comparable scholars like Johan Galtung and Bruce Russett have more citations as Author, because their articles are so widely cited. 8 Another striking thing about Tables 1.1 and 1.2 is that Rummel has extremely limited co-authorship. Only one co-authored article just barely makes into the top-ten article list, and he has no co-authored books. By contrast, leading scholars of the same generation such as Johan Galtung, J. David Singer, and Bruce Russett have numerous co-authored articles and books. Co-authorship, although much less frequent than in the natural sciences where articles can have several hundred co-authors, is becoming increasingly common in the social sciences. In the earlier volumes of Journal of Peace Research, for instance, the average number of authors per article is generally between 1.1 and 1.3 (indicating that on average every third to every tenth article has a co-author, since few articles have more than two authors), rising to an average of nearly 2 for the most recent volumes. 9 One plausible reason why Rummel has few co-authors is that as his daughter reminds us in Chap. 2, he was a rather private person and perhaps not temperamentally 8 The reader may wonder how it is possible to have more citation to Author than to Cited author, when the latter includes all works, including books, whereas the first includes only WoS-indexed articles. The reason is that the Author file counts all article citations individually, whereas in the Cited author file the scholar only gets a single citation from an article that cites several of his/her works. well suited to share the process of writing, although he maintained an active network of academic collaborators and contacts and frequently discussed his work with his students. He had a relatively low number of Ph.D. students. He was a very influential force in their professional lives, as Sang-Woo Rhee explains in Chap. 4, and Doug Bond describes him as the most supportive teacher he ever had. 10 Whether or not he encouraged or discouraged his students to publish while working on their dissertations is not entirely clear, but he certainly shared the prevailing notion that the dissertation had to come first. So did J. David Singer, but unlike Rummel he co-authored extensively, including with former students. And so did Russett and Galtung.

The Critics
Rummel's work has been subjected to extensive examination by other scholars, leading to praise as well as harsh criticism. The DON Project (along with three other major quantitative empirical projects in international relations) was subjected to close scrutiny in Hoole & Zinnes (1976), with separate chapters on the philosophy of science and research design of the project (Hilton, 1976), its methodology and statistical practices (Hazlewood, 1976), and the substantive findings (Van Atta & Robertson, 1976), in addition to a presentation and a bibliography by Rummel (1976d, f) and a brief response to the reviews (Rummel, 1976e). Hilton's chapter built on a detailed review of DON he had done earlier at Rummel's invitation (Hilton, 1973). It is impossible here to summarize all the specific points raised in these reviews. Some of them may have been bypassed by the rapid theoretical and empirical progress in social science since that time. Others, such as the role of theory in international relations research, how to deal with missing data, and the relative role of national attributes and relational characteristics in accounting for international interaction, remain.  Ray (1982, 1998, andChap. 8) was always a constructive critic, who carefully read all five volumes of Understanding Conflict and War, which he characterized as one of the most energetic and comprehensive contributions to the scientific study of international relations. Despite criticism of many of Rummel's answers, he credited him with asking the right questions.
Another friendly critic was Warren R. Phillips, who had himself obtained his Ph.D. under Rummel and had served (1968-71) as assistant director of the DON Project. He was generally quite critical of the lack of theory in the international relations discipline but found Rummel's field theory to be a promising island of theory (Phillips, 1974). Several years later, he was more critical in reviewing Peace Endangered. While Rummel had done valuable work in mapping objective aspects of power (capabilities) his attempt to deal with the subjective aspects (interests and capability) were judged to be inadequate (Ensign & Phillips, 1980). An equally well-read but more critical commentator was Wiberg (1982). While acknowledging the extraordinarily prolific nature of Rummel's scholarship, he criticized Rummel for the tautological nature of his comprehensive field theory, for biased summaries of some major schools in social science (such as frustration-aggression theory and Marxism), and particularly for questionable judgments in his wide-ranging literature review as to whether or not the empirical results from published articles support his theoretical framework, Rummel responded briefly (Rummel, 1983b) and later in a new article summarizing how published articles supported his libertarian propositions on violence (Rummel, 1985: 435, note 6).
Another strong critic was Vincent (1987a, b) who argued that Rummel's interdemocratic peace could not be sustained with an alternative set of conflict data. Rummel responded to this in the same journal issue. But Vincent used conflict data for only a few years in the 1970s, as did Rummel (1983a, b), which Vincent had critiqued. In view of the many analyses of the democratic peace using much longer time series for different well-established datasets, this debate is less relevant today. Rummel's long-time colleague at the University of Hawaii, Michael Haas, had found in an early article 'a slight but consistent tendency for democratic countries to have less foreign conflict' (Haas, 1965: 313), but later became a vocal critic of the democratic peace program (Haas, 2014).
Of great continuing interest is the debate about Rummel's democide estimates. Rummel created these on a country-by-country basis using published studies, concluding with three figures, a high estimate, a low estimate, and a most probable estimate. These could vary significantly. For the Soviet Union, for instance, Rummel (1990: 3) estimated a most probable democide of 62 million people, but with a range from 28 million to 127 million. In most of his work on democide, he focused on the most probable estimates, leaving himself somewhat vulnerable to criticism for excessive precision in these numbers. However, he also noted that he would be amazed if future research did not come up with figures that deviated significantly from his own. His figures should be viewed as rough approximations (Rummel, 1994: vii-xx).
His volume on the statistics of democide, however, as well as the books on the four 'deka-megamurderers' (the Soviet Union, China under Kuomintang, China under Mao, and Nazi Germany), contain all the sources and all the numbers and extensive comments on how he selected his own numbers. Some critics, including Harff (1996: 118) have argued that 'Rummel chooses numbers of deaths that almost always are skewed in the direction of the highest guesses'. In this volume, Barbara Harff (Chap. 12) cites but does not reiterate this criticism. Rather, in discussing Rummel's numbers for Cambodia, she finds that given his wide definition of democide, his estimates are consistent with established estimates in the literature and she also acknowledges his 'monumental job in collecting data and information'. A reviewer of Rummel's volume on democide in the Soviet Union chides him for not using Russian-language sources and for assuming citing a range of secondary sources 'as if they were all of equal worth'. He also faults Rummel for assuming 'that the entire labour camp population was innocent' although some of those who died in the camps 'were common criminals or actual Nazi collaborators' (Swain, 1991).
A critic of Rummel's democide estimates for Yugoslavia (Dulić, 2004a) argued, on the basis of considerable documentation, that Rummel's estimates for democide in Yugoslavia during World War II and in the immediate aftermath of the war were much too high. He also questioned whether similar data problems might occur in other democide estimates. Rummel (2004a, b) thanked him for his contribution to research on democide, but dismissed the overall claims of the critique, since Dulić had only commented on a portion of the time period covered by Rummel. Dulić (2004b) was not convinced.
As Rummel pointed out in his reply to Dulić, it is not enough to criticize the numbers he published. The issues are too important for criticism alone. Those who disagree with his numbers should feel a responsibility to come up with alternative and more reliable figures. Rummel's work on democide was not only a gigantic data collection effort, but also admirable in its transparency-long before the replication requirement became a standard feature of empirical work in international relations.

The Novelist and the Artist
Rummel's novels were written after he finished writing for academic journals and book publishers, but they are in direct continuity of the main themes from his research and were published under the general heading of the Never Again Series. I have only read the first (Rummel, 2004b), but that puts me ahead of most of the other contributors to this volume. The book is packed with love, sex, and action, and written in a rather macho style, quite common in its genre. The basic plot is that the hero, Rudolph Rummel himself in only a slight disguise, enters the past through a time-machine with a female partner, to create an alternative world where major wars and democides have been avoided. Through a mixture of bribery and assassinations, they derail the Mexican revolution, dispose of Hitler, Lenin, and Stalin long before they are anywhere near political power, and prevent the two World Wars as well as the Sino-Japanese War and the democide in China. One might wonder what is left to save the world from in the following volumes, but it appears that the time travelers ran into some unexpected future problems. Rummel's novels were probably too closely tied to his academic and political pursuits to stand much of a chance in the mass market of paperback fiction. The books are still available in electronic form from Llumina Press and from Rummel's website, and hard copies can be obtained from amazon.com. Llumina is a self-publishing press, and the publisher notes that sales of such books depend on the author's ability to promote and market them. In Rummel's cases, the sales were very limited. 11 Apart from their merits as fiction, the six novels reinforce the picture of an exceptionally diligent writer. Each book is 200-300 pages, and all six were published in a two-year period, along with a nonfiction supplement (Rummel, 2005).
Rummel was also an artist and in his later years spent a large part of his time painting. I am even less qualified to comment on his art than on his novels and happily defer to his daughter's comments in Chap. 2. An example of his art is found on the previous page of this book and many others can be found at https://www. hawaii.edu/powerkills/GALLERY.HTM. But as someone who did know Rummel personally, I can testify that the self-portrait reproduced in front of this introduction is a good likeness. That brings me to a few final personal recollections.

Personal Recollections
I worked as research fellow for the Dimensionality of Nations Project in the spring of 1969. My visit had been arranged by correspondence between Johan Galtung and Rudy. At the time their relations were pleasant. Rummel was interested in Galtung's work relating status inconsistency to conflict (Galtung, 1964). Indeed, he actively tried to incorporate what he called status theory into his field theory (Rummel, 1971). But as H.-C. Peterson relates (Chap. 10), the cordiality got lost along the way. For many years they were colleagues in the Department of Political Science at the University of Hawaii. By this time, Galtung held the view that 'international relations US style' was bankrupt and when cut to pieces, it could be deconstructed as self-serving US ideology (Galtung, 1989: 166). Rummel, on the other hand, came to see Galtung's concept of structural violence as a socialist theory of peace within a neomarxist theory of exploitation (Rummel, 1981: 50, 83). The two colleagues hardly interacted. Rummel's relationship to Singer was much less acrimonious, although the two had a life-long disagreement on the prospects of explaining international relations, at least in part, on the basis of national indicators (cf. Wayman in Chap. 9). Rummel's particular mix of realism and liberalism, noted by Erich Weede in Chap. 7, may have made it difficult for him to form lasting alliances with other scholars.
Johan Galtung was my highly valued mentor, but over the years I came to rely more on Rummel's wisdom. As editor of Journal of Peace Research, I published the harsh critique of Understanding Conflict and War by Wiberg (1982), but my friendship with Rummel survived. I can recall two 'friendly quarrels' with Rummel. One was over his Nobel Peace Prize nomination. For years, Rummel had on his homepage that he had been shortlisted for the Nobel Peace Prize. Although the list of nominations is not made public by the Norwegian Nobel Committee, many nominators publicize their nominations and it was on record that Rummel had been nominated several times by former Swedish deputy prime minister Per Ahlmark. I tried to convince Rummel that the nomination itself was not necessarily such an unambiguous honor; indeed Adolf Hitler and Fidel Castro had also been nominated. Furthermore, there was absolutely no reliable evidence regarding the composition of the committee's shortlist. I was pretty certain that Rummel had never been shortlisted and succeeded in getting the committee's secretary to confirm that there was no evidence for it. 12 Evidently, Rummel had confused a news report that talked about a final list (i.e., a list of all nominations received before the deadline) with a 12 Telephone conversation with Geir Lundestad, then Director of the Norwegian Nobel Institute, probably in 2005.
shortlist. Eventually, he stopped referring to his having been 'a finalist', following as he said 'advice from a colleague who I highly respect, is a friend who supports my research, and who is knowledgeable about the workings of the Nobel Committee'. 13 A second friendly quarrel occurred when in 1995 I served as guest editor for a special issue on democracy and peace in the European Journal of International Relations. Rummel published an article on the monadic democratic peace-in fact his fifth-most-cited article. In a previous much longer and widely circulated version, Rummel had promoted the argument that if democracies don't fight each other, the world must necessarily become more peaceful as the number of democracies increases. Although the two referees had not picked up this point, I argued in my decision letter, as I have done elsewhere, that this was not necessarily the case (Gleditsch & Hegre, 1997). We went back and forth. I was prepared to concede the point, which was not central to the article, but not without a struggle. Therefore, I set out to explain my argument in some detail. Finally Rummel wrote back to me. 'Nils, you did it'. 14 I have always felt that scholars should not give up their cherished views too easily. For that reason, I valued Rummel's persistence, although some surely would call it stubbornness. Nevertheless I am happy to have influenced this article and perhaps, even if in minor way, contributed to its success.
Finally, one of the perks of being president of the International Studies Association is the power to award the Susan Strange award to the scholar 'whose singular intellect, assertiveness, and insight most challenge conventional wisdom and intellectual and organizational complacency in the international studies community'. 15 Nothing would have pleased me more than to give this award to Rudy when I served my term in ISA in 2009-but he had already received the award! In fact, he was the first, in 1999. I can think of no one more qualified in terms of challenging conventional wisdom and intellectual complacency.

A Final Assessment
Rudy Rummel was a many-faceted scholar. It was not difficult to find things that you could disagree with. But there was also much to admire. His scholarly productivity. His enormous contributions to data on democide. His consistent commitment to freedom and his marriage of research and policy advocacy. His pioneering example in making data and research procedures transparent. His early use of the internet and his comprehensive homepage, matched by few if any social scientists of his generation. Hopefully, this little volume will inspire some readers to go back to Rudy's own work, for inspiration and for contradiction, but above all to follow his lead in seeking new knowledge for a better world. 13 See at: http://www.hawaii.edu/powerkills/NPP.FINALIST.HTM. 14 Or something to that effect. I can no longer find the correspondence. 15 See at: http://www.isanet.org/Programs/Awards/Susan-Strange.
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