This article suggests that existing negotiation theory, which is dominated by the two paradigms of 'bargaining' and 'problem-solving', does not capture some important characteristics of international negotiations. It is argued that 'genuine debate' encapsulated by Habermas's concept of 'communicative action', which has largely been ignored in the negotiation literature, furthers and complements our understanding regarding negotiators' rationale for action and the dynamics of international negotiations. The paper specifies five conditions conducive to genuine debate: (1) a strongly shared lifeworld among negotiators; (2) uncertainty and lack of knowledge; (3) technical or cognitively complex issues; (4) the presence of persuasive individuals; and (5) low levels of politicization. My hypotheses are probed through a case study of EU negotiations concerning the WTO basic telecommunications agreement. My findings imply that genuine debate may occur most likely in pre-negotiations and at the diplomatic level of negotiations. I also conclude that agreements arrived at through genuine debate tend to be more enduring than those reached by bargaining and problem-solving, and that communicative negotiators are vulnerable to those merely pretending to participate in genuine debate. My analysis also tentatively indicates what kind of arguments may be persuasive in genuine debate.