‘Isolationism’ is a much used and abused term in the contemporary American foreign policy debate. This article seeks to illuminate some of the misunderstandings that surround the use of this term by challenging seven persistent myths about isolationism. In so doing it sheds light on the often unarticulated role that this and other ideas play in the US foreign policy debate. It also seeks to demonstrate the nature of the main ideational cleavages within this debate which the isolationist name-calling obscures, and to show the way in which language is used in the political discourse and how its meaning in this debate changes over time.