BACKGROUND England, Australia and the United States have approached the regulation of e-cigarettes in very different ways, yet all three countries have appealed to the concept of evidence as underpinning policy responses. We compared these policy responses using a combination of the methodologies of historians and policy scientists in order to elucidate the factors that had influenced policy in each country.

ARGUMENT/ANALYSIS Each country's evidence and values intersected in different ways, producing very different responses within specific national contexts and histories. Our analysis accordingly emphasized the historical precursors of the policy issues raised by e-cigarettes and placed the policy debate within the context of regulatory bodies and the networks of researchers and advocates who influenced policy. Issues also of importance were the nature of the state; political context; the pre-history of nicotine for smoking cessation; the role of activism and its links with government; the influence of harm reduction ideas from drugs and HIV; and finally, whom policy was perceived to benefit. In the United Kingdom, based on this pre-history of the smoking issue, it was the existing smoker, while in the United States and Australia, protecting children and adolescents has played a central role.

CONCLUSIONS Structural and historical factors appear to underpin differences in e-cigarette policy development in England, Australia and the United States.