Civilian casualties and support for war: A comparative study

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Principal investigator:

Robert Johns

University of Essex



Sample size: 2072

Field period: 1/18/2010-3/31/2010


There are some significant gaps in the large and growing literature on public support for military action. One concerns its comparative scope: the vast majority of research is on the US alone. Another is the neglect of civilian casualties: it is the relationship between military casualties and support for war that has preoccupied researchers to date. This TESS survey carried two experiments identical to those fielded in a contemporaneous survey of British foreign policy attitudes, and these experiments form the basis for two papers.

In the first, we manipulate two characteristics of the target state, regime type and dominant faith, to test whether the “democratic peace” and the “clash of civilizations” theses are reflected in U.S. and British public opinion. The second examines the US and British publics’ support for air strikes against Iran’s nuclear facilities, and tested whether this support would be dampened by the prospect of civilian casualties. We manipulated both the number and the framing -- as 'civilian casualties' or 'ordinary people' -- of casualties.


H1: Support declines with a) the mention, and b) the number of expected civilian casualties

H2: The impact of civilian casualties is intensified when framed in more ‘humanized’ terms

H3: The negative impact of civilian casualties is dampened in cases where:

(a) military action is likely to be more successful
(b) the target state is not a democracy
(c) the target state is Islamic rather than Christian

H4: The impacts of situational factors posited in H1-3 are moderated as follows:

(a) civilian casualties have a weaker impact on citizens higher on nationalism and authoritarianism
(b) religious similarity has a weaker impact on non-religious citizens

H5: The moderating effects in H3(c) and H4(b) are stronger in the US than in Britain

Experimental Manipulations

Experiment 1

Today the American government has presented evidence to the United Nations that Country A has been developing a secret nuclear weapons program which it intends to use against its neighbors in the region. The government is making the case for air strikes against factories associated with this program. Professor Andrew Lincoln, a leading expert on military strategy, has estimated that the planned American air strikes would result in the deaths of around one hundred/ three thousand civilians/[sentence omitted]. The democratically-elected President/unelected dictator of Country A, a predominantly Christian/Islamic country of around 20 million people, has strenuously denied the American government’s allegations.

Experiment 2

Western governments, including the American, have long expressed concerns about Iran’s nuclear ambitions. In particular, they claim that Iran has secret facilities that are being used to develop nuclear weapons. Iran has consistently denied that these claims are true but, according to the American government, Iran is not far away from being able to launch a nuclear strike. The American government is considering air strikes against the Bushehr nuclear facility, which it says is producing the nuclear materials necessary for Iran’s weapons programme. Since this facility is in a populated area, air strikes are likely to result in civilian casualties/ordinary Iranians dying. Professor Anna Knott, an expert on the region, estimates the likely civilian death toll at around 50/500/5,000/50,000 people. She adds that air strikes are likely to slow down Iran’s nuclear weapons programme by one year/ten years.


Experiment 1

a) On a scale from 0 (strongly oppose) to 6 (strongly support), how do you feel about British/American air strikes in this case?

b) And if you had to choose ‘oppose’ or ‘support’, which would you go for?

Experiment 2

a) On a scale from 0 (strongly oppose) to 6 (strongly support), how do you feel about American/British air strikes in this case?

b) In addition to air strikes, there are other options open to the US/British government. Here are various courses of action – please choose the one that you think the government should follow.
o Invade Iran to remove the regime
o Air strikes (as described above)
o Impose sanctions on Iran (e.g. stopping the country from selling oil)
o Negotiate to try to persuade Iran to stop developing nuclear weapons
o Nothing – Iran is not a threat

Summary of Results

Experiment 1

This experiment tested whether the 'democratic peace' and the 'clash of civilizations' theses are reflected in US and British public opinion. The basic findings show small differences across the two cases: both publics were somewhat more inclined to use force against dictatorships than against democracies, and against Islamic than against Christian countries. Respondent religion played no moderating role in Britain: Christians and non-believers were alike readier to attack Islamic states. However, in the US, the dominant faith effect was driven entirely by Christians. Together, our results imply that public judgments are driven as much by images and identities as by strategic calculations of threat.

Experiment 2

Support for military action against Iran, while clearly the minority position in both the US and the UK, was markedly stronger in the former, being driven more strongly by various aspects of conservatism. And the American public was generally less responsive to the experimental manipulations, also suggesting that the issue is more politicised in the US and so more minds are already made up. In particular, the prospect of civilian casualties did less to dampen support for war in the US. The main reason is that those scoring higher on authoritarianism and related personality variables were largely impervious to such casualties, unlike in Britain where responses to civilian deaths were consistent across the sample.

With the exception noted above, we tended to find few situational or predispositional moderators of reactions to civilian casualties. It seems that concern about casualties is potentially widespread, suggesting that this is not a case of "don't care" but instead one of "don't know" -- because public discourse about war doesn't prime consideration of civilian deaths.

Additional Information

The British data come from a major survey of foreign policy attitudes, funded by the Economic & Social Research Council (RES 062-23-1952), into which these and other experiments were embedded. By the end of 2012, the data will be archived and available via the Economic & Social Data Service (


Johns, Robert and Davies, Graeme A. M. (2012), "Democratic peace or clash of civilisations? Target states and support for war in Britain and the USA", Journal of Politics, 74(4), 1038-52.

Johns, Robert and Davies, Graeme A. M. (2012), ""'A tough sell'? US and UK public support for military action in Iran"", presented at the Annual Convention of the International Studies Association, San Diego, CA, 1-4 April.