Nissan Motor Co's decision to back out of its planned investment in its Sunderland plant has (surprise!) divided opinion in Britain along pro- and anti-Brexit lines. "It's not you, it's me" was the message Leavers read into Nissan's statement. It wasn't meant to be, they shrug. And, anyhow, Nissan is sticking around to make other models in Sunderland.

Those worried that Brexit is making Britain uninvestible focused on Nissan's understated admission that "the continued uncertainty around the United Kingdom's future relationship with the European Union is not helping companies like ours to plan the future." The message they heard: "You Brits don't know what you want, so we're out of here." And they're probably right: This is a sign of more to come.

Of course, Nissan had plenty of other reasons to abandon plans to make a diesel model of its X-Trail sports utility vehicle in Sunderland. Take your pick: The collapse in diesel demand, changes to emissions regulations, a slowdown in China, its own corporate dramas and a flattening European market. But to exclude Brexit from that list would be to ignore the broader 46.5 percent decline in 2018 in investment in the U.K. auto sector and the general slowdown in spending across other parts of the economy.