Brexit is due to be completed in less than a year, which will have a fundamental impact on the UK's trading relationships with the rest of the world. In this Vox Talks, Alan Winters discusses how modern trade agreements are made, and why they are harder to negotiate than many assume. In order to avoid huge disruptions of trade, the UK must negotiate new agreements across the globe - a task made more difficult by the need to harmonise the sometimes contradicting regulations of different countries.