The purpose of this paper is to review the scientific basis for claiming any effect of foreign information operations. The literature on information operations is reviewed, as well as other kinds of persuasive communication (advertising, risk and health communication) that aims to change attitudes or behaviour. Most research indicates that persuasive communication in general has little effect on receiver attitudes and/or behaviour. Some hypothetical strategies that may increase the effect are formulated, such as hiding the sender’s intent, sending messages not too distant from the receiver’s present views, or using the emotional, rather than the rational, route.