Approximately one month into the Iran war, public opinion on both sides of the Atlantic is decidedly opposed to this conflict. A recent CBS/YouGov poll shows that 60% of the public oppose military action against Iran, as do a similar percentage in the UK: 59%.
As a political scientist who studies public attitudes about foreign policy and the use of force, my research addresses an important question: under what conditions do people support military action? Based on this research, the widespread opposition to American military action against Iran is completely understandable, as the action lacks the usual foundations for support from domestic as well as international audiences.
Decades of research in political science show that broad support for use of the military rests on three key pillars: purpose, likelihood of success and legitimacy. When these elements are present, support can be high. It can even be maintained in the face of significant costs, both financial and in terms of lives lost. When they are absent, support tends to be weak, polarised and prone to erosion.
