This chapter compares the postures of Iceland and Denmark towards the United States and NATO over time. It explains why both states became strong, unflinching allies of the Unites States after the end of the Cold War despite their contentious relationships with the Unites States during the Cold War. Having hesitatingly joined NATO and signed a military basing agreement with the Unites States, Iceland was a rebellious and extractive ally throughout the Cold War. It threatened repeatedly to leave NATO and/or to expel US forces from Icelandic soil and extracted considerable economic and diplomatic benefits. However, Iceland became highly compliant with US policy after the end of the Cold War. Denmark was a reluctant and transactional ally during the Cold War with the political elite and the public viewing NATO membership as a necessary evil. However, after the end of the Cold War, Denmark became a highly compliant ally, as it expended considerable blood, treasure and political capital to support US priorities and military operations. We show how in both cases the demand for security shelter, coupled with the worldviews and ideas of domestic elites, helped shape the transatlantic relations of the two countries.