Absence may make the heart grow fonder, but distance also clarifies the mind. A fortnight’s visit to Japan put the impact of Brexit on Britain’s reputation around the world in a dazzling light.

On the face of it, Japan ought to be a far better model for post-Brexit Britain than the oft-cited city-states of Singapore and Hong Kong. A proudly independent island-nation of 125 million people off the coast of Asia, trading with the world and highly resistant to immigration, if Theresa May has ever been there she must surely have noticed that Japan ticks most of her boxes. Few, if any, Japanese think of themselves as “citizens of the world”.

Yet, at event after event, meeting businessmen, diplomats, bureaucrats, students and journalists, this correspondent heard an utterly consistent message: “We have always admired you British. So why have you now gone mad?”

If you travel in the United States you will hear plenty of people who side with the Brexiters. Some Americans, after all, helped finance and organise the Leave campaign. Others instinctively share Eurosceptic distrust of Brussels bureaucrats and see parallels in their own hatred of Washington.

Not in Japan. There, the questions came thick and fast about Brexit and what we British thought was the point of it. For example, I was asked, by a former senior diplomat: “Why do you want to make yourselves weaker and more vulnerable?”.

He went on to point out that “We Japanese also have a ‘special relationship’ with the United States over security, but we have long envied the fact that your EU membership has added to your leverage with the Americans: why are you giving that up?”

He and other said: “We’d like to have a closer relationship with other countries in Asia, on security as well as economics, but both China and our history stands in our way. How we wish we were like you, dealing with France and Germany instead. Now that President Macron has been elected, can’t you change your mind?”

Business figures acknowledged that their arguments that Britain should stay in the single market are a matter of self-interest and convenience for Japanese firms that have invested in our country, but they wondered, “doesn’t that make the single market and customs union matters of self-interest and convenience for you, too?”

“We keep hearing your ministers say that all countries have ‘access’ to the single market, often citing Japan, but don’t they realize that the single market and the EU’s common external tariff are precisely why we have built factories in the UK? ‘Access’ from outside the EU is much inferior to access from within the single market.

“Oh and by the way, why is your now tighter immigration policy also penalizing us Japanese?” A Japanese journalist now moving to London as a special correspondent for their newspaper reports having to pay £1,000 for the visa, plus a £500 deposit for use of the NHS, and reams of paperwork for bringing in their possessions – none of which applied the last time they resided in London in the 1990s. As this special correspondent has a European beat, they now wonder whether their successor might be better placed in Paris, Berlin or Brussels.

Most of all, the refrain was pained and somewhat despairing: “Emmott-san, we always used to think of the British as being deft diplomats and full of good common sense. Now you seem awkward, incompetent, chaotic and often nonsensical. Please tell us that you are going to come back to your senses soon”.

My answer was consistent too. “I really wish I could.”

Edited by Sam Ashworth-Hayes