Trade deals, like peace agreements, aren’t worth the paper they’re printed on without good faith vested in their implementation.

Just weeks after the Brexit trade agreement entered into force, intentions over the part of the deal that applies to Northern Ireland have been called into question by both the U.K. and the European Union. Once again, the relationship between the two sides hinges on resolving differences around trade across the Irish border..

To make a long story short, the U.K. is claiming the new trading rules for Northern Ireland aren’t working, but the EU says a deal is a deal and Britain must abide by its treaty commitments.