This chapter examines posed for the first time a number of questions related to the transatlantic protection and transfer of personal data in the fight against terrorism and organised crime. It shows that before the 9/11 attacks Europol and the US did not conclude any agreements, highlighting the significance of broader socio-political events and political priorities in affecting whether an issue emerged high on the political agenda of actors. The chapter also shows that the 9/11 attacks worked as an external crisis that initiated a learning process among both Europeans and Americans. It presents the historical context of the relations between Europol and the US and it shows that both sides placed emphasis on the importance of international law enforcement cooperation. The chapter focuses on the agreement for the exchange of personal data given that the strategic agreement was routinely negotiated and concluded without any blocks emerging.