This article examines the tensions that arose within transatlantic relations when Greece, a NATO member state, began to violate its citizens' human rights and civil liberties following a military coup in 1967. It considers and analyses NATO's subsequent reluctance to put effective pressure on the Greek regime, despite the fact that all member-states, barring Portugal, were united in their revulsion for it. It looks at how allies ended up at odds on how best to deal with such a dictatorship. It scrutinises the tactics employed by Manlio Brosio and Joseph Luns, Secretaries-General of NATO, to ensure that conflict within the Alliance over the Greek issue was contained and that Cold War priorities retained precedence. Finally, it evaluates the long-term ramifications of the Greek case on transatlantic relations.