Parallax error is the kind of thing one learns about in year five physics. It describes the way the same object can appear to have different qualities observed from different angles – like a measuring gauge, for example, or Arsenal’s talented teenage centre-forward Eddie Nketiah.

“Arsenal wonderkid Eddie Nketiah nets hat-trick for England Under‑18s,” was the headline in one English newspaper after Nketiah’s fine performance against Qatar on Tuesday night. “England-born Ghanaian Eddie Nketiah scores on England debut,” was an alternative view from Ghanaweb.com after Nketiah had scored on his debut against Saudi Arabia last week.

Wilfried Zaha hits back at Southgate’s ‘timescale’ claim over England selection Read more

This is slightly more than a parallax error. It is Nketiah’s good fortune, and indeed a function of modern life, that he can inhabit all these identities at once: Arsenal wonderkid, England Under-18, England-born Ghanaian.

International football may soon demand he settles on a more exclusive classification although, if that time comes, Nketiah may just feel a little uncertain, perhaps even a bit more Ghanaian, after the bizarre furore this week over Wilfried Zaha’s decision to play for Ivory Coast.

These are of course complex issues. Only the most blinkered observer could fail to acknowledge the parallax error here; or insist that to feel doubts, to have divided loyalties, to turn away from dear old Albion represents a kind of failure, a deviation from the true, the pure, the best.

At which point enter Danny Mills, Gareth Southgate and quite a few other people with fixed and punitive opinions on Zaha’s identity as a footballer. Born in Abidjan, Zaha came with his eight siblings to live in Thornton Heath aged four. He has always been open about his interest in playing for the country of his birth. Five years ago he told Dominic Fifield of the Guardian: “It’s 50:50 because I was born in Ivory Coast but all I know is England. When the time comes, I’ll make a choice.”

The English Football Association made exceptional efforts to sway that decision. When Zaha was 19 the stand-in England manager Stuart Pearce made a much-trumpeted visit to Crystal Palace’s training ground to plead for his teenage loyalties. Zaha was swayed. Despite Didier Drogba’s best efforts he accepted a call-up to the senior team the same year – but only after senior FA figures had spent hours reassuring Zaha he would not be jeopardising his chance of representing Ivory Coast in the future. In the end Zaha played 21 minutes for England. His last cap came in 2014. Until recently his form did not demand much more. The former Palace owner Simon Jordan has suggested Zaha simply was not “organised” enough to make that step up. On the other hand a total of 53 England players have been picked since Zaha’s last cap. Rickie Lambert, Jonjo Shelvey and Calum Chambers got more of a run in the team.

And so here we are. As a 19-year-old, Zaha was persuaded to commit one way. It did not work out. As a 24-year-old it seems entirely correct, having been courted by the Ivorian FA for years, that he should now decide to play instead for the country of his birth. Last week he scored a brilliant goal against Russia and looked a happy footballer in the right place. Case closed, surely. Everyone wins. Another example of mixed but equally legitimate sporting identity resolved.

Except apparentlyApparently not. For Mills, who is from Norwich and who has never had to contend with any clash of nationalities, Zaha’s decision to choose his birth nation is to be condemned. It shows a lack of “fight”. Zaha is simply “taking the easy option”. It is hard to know where to start with this combination of parallax error and solipsism. Never mind that Ivory Coast is hardly an easy option, given the logistics and internal politics involved. Never mind this is a nation that has actually won an international trophy recently and fielded at least as many genuinely top-class players as England in the last few years. Not to speak of the private issues of family and heritage that, frankly, demand a little more respect.

There is simply a startling insularity here, not least in the assumption that playing for England is somehow more real, more authentic than playing for anyone else; that a passion for any other nation must be an inferior, B-list passion, a cop-out. The road from Laurie Cunningham to Raheem Sterling – via John Barnes, Ian Wright and Ron Noades – is a long one, and largely a happy story of integration and acceptance. But there is no doubt some element of tension exists here, which Zaha’s choice has gouged open.

Far more significant is Southgate’s response, which like that of Mills was honest but also judgmental. Southgate has said he also sees a lack of “inherent desire” in Zaha’s choice, an absence of “internal 100% passion”, citing Jermain Defoe as an example of a 100% passionate desire-filled Englishman.

This is, of course, a false comparison. Had Defoe chosen to play for St Lucia or Dominica, then this would not be evidence of lack of passion but simply a choice to be respected, as should the choice to play for England.

Gareth Southgate wanted Wilfried Zaha for England role but was too late Read more

Similarly Southgate’s desire for only 100% committed Englishmen is a little bizarre in a nation where so many people are simply not 100% one thing or the other and where it is deeply crass to cast split loyalties as an issue of blame and unworthiness, an absence of guts and spleen and old English backbone. We are just a sideways leap here from forced anthem singing, thought crimes against the Queen, competitive flag-fondling.

This comes at a time when mixed nationality England players are increasingly common. Zaha’s home patch, Croydon’s A23 corridor, is a place of huge ethnic diversity and also the most potent hotbed of domestic talent. Currently 14% of English footballers in the Premier League are from that square 10 miles.

Should the London-Croydon heartland declare national independence it could field a current XI of Jamal Blackman, Nathaniel Clyne, Joe Gomez, Chris Smalling, Ryan Bertrand, Jason Puncheon, Ruben Loftus-Cheek, Ben Watson, Jordon Ibe, Victor Moses and Zaha. The majority of these qualify for at least two nations. Look one layer down and the England Under-21 team is stuffed with dual or triple footballing nationals. Against Lithuania last week the senior team had four on the pitch who might have opted to play for Jamaica.

This is simply England, like it or not. Just as the nation’s wealth was built on empire, so the rump of its football team is likely to come in the next few years from a hugely diverse young population. Throughout this, hopefully in the background, choices will have to be made, identities firmed up, some sporting loyalties expanded, others abandoned. The ability to understand rather than bully or cajole, or make absurd, badge-kissing value judgments is the only viable future here.

One thing is certain, though. In a week when the response to Zaha’s choice has been veiled anger, a suggestion of weakness and character-deficit in opting for anyone other than England, it will be a slightly unhappier, less certain process for the those to come.