05/09/2016 05:37 BST | Updated 02/09/2017 06:12 BST

Good News Travellers - You Can Now Fly Direct From London Heathrow To Tehran's Famous Evin Prison

So they're back. Direct flights from London to Tehran, that is. After a four-year break, including delays for "technical" reasons after originally announcing flights would resume in July, you can now fly British Airways from London Heathrow to Imam Khomeini International airport.

Hooray! Er, well, I suppose it's good if you want to fly between these two particular countries (and think BA's £600-1,300 ticket is worth the money).

BA certainly think it's something to celebrate. This is what its website says awaits you after the six-hour flight:

One of the biggest cities in the Middle East, Tehran is a bustling metropolis with a large, friendly population. Sitting at the foot of the beautiful Alborz mountain range, its climate is perfect with warm dry days and cool evenings. All over the city you'll find lush parks and gardens, plenty of museums and galleries, brilliant shopping, and a rich and diverse cuisine. And while Iran may have a strict conservative government, change is coming. More than half of the population is under 30-years-old and the younger crowd are reinventing the city, which is slowly becoming a hub of contemporary arts with a changing social scene. Iran is a beautiful place, and Persians are a welcoming and hospitable people, with an ancient culture and rich heritage that deserves to be explored.

OK! Lush parks. Brilliant shopping. Diverse cuisine and friendly people (so much better than unfriendly ones). But "strict conservative government"? Oh no, that's a bit of a mood-killer. On the other hand, "change is coming" so ... er, that's probably alright ...

Except, what about if it's not alright. If, for example, you're a UK-Iranian dual-national like Kamal Foroughi or Nazanin Zaghari-Ratcliffe you might find that flying from London to Tehran involves rather more than meeting friendly people and shopping for "famous brands" in the Arg Commercial complex. Because both of these British nationals are currently behind bars in Tehran's notorious Evin Prison. Both were regular visitors to the country (one a businessman, another a charity worker with family in the country) before the security services swooped.

As Radio 4's The World Tonight programme has suggested in a discussion of the topic, there are reasons to believe that dual nationals are being specifically targeted by factions within the Iranian authorities unhappy with what the recent nuclear deal may mean for their own grip on power. The thinking is that through such detentions the conservative Revolutionary Guards entrenches their power and undermine the influence, prestige and bargaining power of the (mildly) reformist president Hassan Rouhani.

A reasonable assessment? Could be, but to be honest I can't really pretend to know. What's not difficult to assess is the fact that, for one, Foroughi is still in jail despite having served considerably more of his sentence than would normally be required under Iran's usual early-release rules. And as for Zaghari-Ratcliffe, she was (in a familiar pattern in "security cases" in Iran) held for weeks at a secret location after her arrest in April. In both cases the prison authorities have apparently cared little for the health and well-being of their UK detainees. Meanwhile, in another not dissimilar case, the Iranian-Canadian dual-national Homa Hoodfar (an academic accused, among other things, of "dabbling in feminism") has recently been hospitalised after her health deteriorated in Evin following her arrest in June.

In its travel advice on Iran the UK Government acknowledges "a risk that British nationals and British/Iranian dual nationals could be arbitrarily detained in Iran". "The security forces may be suspicious of people with British connections", says the advice.

Hmm. Those lush parks and brilliant shopping centres are suddenly sounding a little less attractive. (And by the way, recalling that police in Tehran recently broke up a birthday party in a garden and arrested 150 young people - apparently for being at a mixed-gender gathering "next door to an illegal music recording studio" - it isn't as if those Tehran parks and other green spaces are oases of toleration for locals either ...).

But if things are risky for dual-nationals visiting Iran, they're much worse for resident Iranians. Especially if they're politically active in opposition circles, if they're lawyers who take on human rights cases, or if they're independently-minded journalists.

Anyway, I've just checked the BA site again. I'm always torn about making these kinds of bookings. Direct flight or with a change? Is it worth considering business class (complete with "comfy chair", "memory foam headrest" and "luxury amenity kit with skincare products and accessories") or is that a waste of money? Or maybe more pertinently in the case of Iran, shall I just get the single ticket because I might not need the return?