The withdrawal agreement is less than a year old, and the UK seems keen to sit on what was agreed: control and prevent the importation from Britain into Northern Ireland of goods that do not comply with EU regulatory requirements.
The temporary veterinary deal proposed by the EU (which - by the EU's standard - is most flexible and constructive) has been summarily rejected.
Expect the EU to react, and react quickly. The blueprint is the retaliatory duties it imposed against the US in 2018, in a matter of months.
Watch that space. Brace for high duties against goods imported into the EU from Britain, imposed quickly, where it hurts most (NOT Northern Ireland).
And be sure to be on top of your rules of non-preferential customs origin, those that matter for such measures. If you have been caught between the EU hammer and the US anvil before, you'll know what I am talking about. If you haven't and don't know, don't hesitate to reach out.