- Wallace, Michael D. 1979. "Arms races and escalation: some new evidence." Journal of Conflict Resolution 23: 3-16.
- Weede, Erich. 1980. "Arms Races and Escalation: Some Persisting Doubts." Journal of Conflict Resolution 24(2): 285-287.
- Wallace, Michael D. 1980. "Some Persisting Findings: A Reply to Professor Weede." Journal of Conflict Resolution 24(2): 289-292.
- Altfield, Michael F. 1983. "Arms Races? — And Escalation? A Comment on Wallace." International Studies Quarterly 27(2): 25-231.
- Diehl, Paul F. 1983a. "Arms Races and Escalation: A Closer Look." Journal of Peace Research 20(3): 205-212.
- Diehl, Paul F. 1983b. "Arms Races and the Outbreak of War, 1816-1980." PhD dissertation. Ann Arbor, Ml: Department of Political Science, University of Michigan.
- Diehl, Paul F. 1985. "Arms Races to War: Testing Some Empirical Linkages." Sociological Quarterly 26(3): 331-349.
In 1979, Michael Wallace published a pathbreaking study in which he found a very strong relationship between the existence of an ongoing arms race between two countries and the escalation of a militarized dispute between them to war. Looking at 99 militarized disputes among the major states between 1816 and 1965, he found that 23 of the 26 disputes that escalated to war were characterized by an ongoing arms race (Q = 0.98 and phi = 0.80). In other words, if an arms race was going on between two countries, there was an 82% chance that a militarized dispute between them went to war. On the other hand, only about 4% of the disputes that occurred when both countries were not arming at abnormally high rates escalated to war (Wallace, 1979).
Wallace's conclusions were an empirical challenge to many long-held assumptions about politics among nations, including some of the foundations of deterrence theory. However, as Weede asserted, Wallace's results were not inconsistent with the para bellum hypothesis: 'according according to most realist or conservative thinking in the West... the most dangerous occurrence is not a runaway arms race but the status quo powers losing the arms race' (Weede, 1980, pp. 286-287). In other words, if a revisionist power strives to overturn the balance of capabilities, it is likely that both the revisionist and the status quo states will show high growth rates, but the relevant change is that of the power balance, not the rate of arming. In answer, Wallace used the ratio of expenditure growth rates between revisionist and status quo states to determine who 'won' the race.
There was some small difference in escalation between a 'victory' on the part of the status quo state or the revisionist one, but the relationship is much weaker than Wallace's original test (Wallace, 1980). A further test, using a static measure of comparative capabilities (the ratio of absolute military expenditures between the revisionist and status quo states) rather than the dynamic ratio of growth rates, achieved even weaker results for the para bellum hypothesis (Wallace, 1981). These findings lend support to Wallace's conclusion that it is the arms race itself, rather than the power balance, which is dangerous.
The two supports of Wallace's study, the disputes he used and the index he employed, both suffered massive criticism. The problem with the sample was that the strength of the findings seemed dependent on the division of the obviously multilateral World Wars into dispute dyads, hence overweighting the arms races that preceded those wars. If a small number of arms races make up the bulk of the supportive findings, it is evident that the certainty with which one is able to make general conclusions about the relationship between arms races and war is undermined.
The index that Wallace used to determine the existence of an arms race was also challenged. On theoretical grounds, it has been attacked as placing too great an emphasis on the last two years of military spending before a crisis, therefore capturing war preparations rather than an independent arming process. A further problem is that the index is multiplicative - the final index score for the dyad is arrived at through multiplying individual country scores together (Altfeld, 1983). It is conceivable that heavy unilateral buildups could be mistaken for arms races. Certainly in the former case, but possibly in the latter as well, conclusions drawn about the relationship between arms racing and dispute escalation might be overstated. A truly complete study would demand that the index be replicated, but that has yet to be done...
Diehl's work (1983a, b, 1985) on the subject of the relation of arms race and dispute escalation is an independent alternative to that of Wallace (1979, 1980, 1982, 1983, 1990). Although he criticizes Wallace at length, he does remain focused on the real issue by offering an alternative means of testing the identical proposition. Unlike Michael Wallace, he found little connection between arms races and dispute escalation. Fewer than 30% of the disputes that he finds occurring during an arms race escalate to war. The corresponding correlation coefficients are very different: Yule's Q drops from 0.98 to 0.42, and phi is an unimpressive 0.13 (Diehl, 1985, p. 338).
Diehl objects to Wallace's findings on both grounds: that his dispute sample was overweighting the World Wars, and that reliability and validity of his index were questionable. Therefore, he offers both a new index and a new set of disputes. In doing this, the criticisms of Wallace's work fail to be compelling because it is impossible to determine the extent of the effects of each weakness. We can certainly guess that both the dispute set and the index are flawed, but without being able to compare them to anything it is impossible to tell whether or not the assertion is true, or, more importantly, what particular influence these factors have had on the conclusions Wallace has drawn. Without such a comparison, it is impossible not to consider the possibility that Wallace has just found a superior means of dividing dangerous from non-dangerous arms buildups.
From: Sample, Susan G. 1997. "Arms Races and Dispute Escalation: Resolving the Debate." Journal of Peace Research 34: 7-22.