At first sight, the East Asian financial crisis represents an instance of Japan failing the test of regional leadership - as evidenced by its abandonment of initial proposals for an Asian Monetary Fund (AMF) in the face of US and Chinese opposition in 1997. However, if a second look is taken, and one which is sensitised to the fundamental characteristics of its diplomacy, then Japan can be seen as far more effective in augmenting its regional leadership role than previously imagined. Indeed, this article demonstrates that Japanese policy-makers have resurrected, over the longer term and in different guises, AMF-like frameworks which provide a potential springboard for further regional cooperation. Hence, the aims of this article are twofold. The first is to demonstrate the overall efficacy of Japanese regional economic diplomacy, and its ability to control outcomes through steering East Asia towards enhanced monetary cooperation. The second is to explain the reasons behind Japan's distinctive policy approach towards the financial crisis and general lessons for understanding its foreign policy. The article seeks to do so by asking three fundamental questions about the 'what', 'why' and 'how' of Japan's regional role: 'what' in terms of the dominant behavioural patterns of Japan's economic diplomacy; 'why' in terms of the motivations for this behaviour; and 'how' in terms of Japan's instrumentalisation of its regional policy.