Preferential trade agreements have become a tool for the external institutionalisation of a state’s preferred economic governance model, with the US and EU at the forefront of exchanging market access for acquiescence of their preferred rules. The institutionalisation and codification of the relationship with the TTIP was intended to create the world’s largest market and largest regulatory institutional arrangement, whose structural power and gravitational pull would bring other states towards it and its rules and norms. It should have been the Treaty that would bring an end to bilateral treaties. However, the underlying differences in EU and US preferences on this, as revealed in the comparison on recent agreements in this chapter, the potential for politicisation and contestation, and the importance of power asymmetries in negotiations have derailed negotiations. Yet these challenges were severely underestimated at the highest political levels, when the original ambitions for TTIP were set out.