All through the 1950s and 1960s NATO had secretly utilized a secret flight path, called Amber Nine, over the southwestern part of Sweden. The Swedish government condoned the frequent overflights, despite the fact that Sweden was at the time professing to follow a policy of neutrality in the power struggle between the two superpowers. This article argues that the frequent American use of Amber Nine should be viewed as a materialization of Sweden's consent to US hegemony, and that Amber Nine effectively made Swedish airspace and airports a part of NATO's infrastructure. It also makes the case that the arrangement contributed to the eradication of the credibility of Sweden's policy of neutrality, and that NATO's routine use of a flight path over Sweden, a non-NATO country, warrants a reinterpretation of Sweden's role in the Cold War on NATO's northern flank, as well as challenging the definition of the NATO alliance.