Despite NATO’s recent revaluation as a source of legitimacy for American security policy following the Iraq war, Washington will continue to see NATO primarily as an instrument for implementing its own views on international order. This article analyses key points pertinent to the American debate on NATO such as the expansion of the portfolio as well as the institutional development of the alliance. Within the coming months transatlantic conflicts might evolve around possible enlargements of the alliance as well as the question of burden sharing during NATO missions, specifically in relation to Afghanistan. Moreover, NATO-EU relations will remain difficult, given that there is a lack of political will among the parties to make both organisations complement one another.