The EU started this particular game of iterative prisoner's dilemma with the assumption of cooperation. That trust in was betrayed in the first round, and now we're seeing the reaction. Considering the supply chains cross many borders, there is a good chance this will now escalate further, and total production capacity may well be harmed as a result, which is exactly why cooperation was the first choice. It may have been naive in a practical sense to assume that Johnson and, at the time, Trump would be capable of thinking two steps ahead. But getting burned on an assumption of good faith isn't exactly the worst thing in the world. Plus, once the US, UK, and Israel are done, and with more capacity coming on-line, the spigot will turn to the EU and the difference may end up being far smaller than one might think from just extrapolating current data.