Trade deals

The classical economists demonstrated that if country A imposes restrictions against country B, then wealth in country B is optimised if it does not impose retaliatory tariffs. Which makes trade deals pointless and irrelevant. Just open the doors.

Obviously we do not want people selling 110 volt appliances when the national supply is 240 volts, and chlorinated chicken should be marked at least with its country of origin, but the general principle holds. A lot of issues with standards can be dealt with by control at the retail end, so that responsibility passes up the supplier chain to the importer (or manufacturer in the UK, for that matter).