London in particular is a massive international travel hub. It’s a part of the EU (for a few more weeks...), not an isolated island.

NZ has nothing that comes close. Australia is about a 4hr flight away.

but being a travel hub does not mean too much: you can still isolate people who enter the border.

People in transit infect each other, and workers are exposed to more chances to get infected, but it's a more manageable situation than land borders.

I disagree. The UK’s economy is far more international than New Zealand’s. The U.K. ranks 4th worldwide for international travellers per capita, and New Zealand 38th. Shutting down air travel to the financial centre of the world would have been an incredibly risky move at the time. It may have been the right move in hindsight, but at the time it was far easier for the tiny island on the edge of the world to even consider doing it.

I don’t mean in march necessarily. But the UK never implemented testing at the border or isolation for travellers in any rigorous way.

They could have done this sometime over the summer. Going zero covid has huge economic benefits. And with testing you could let business travellers in with a modified isolation.

It was only worth doing in March. Because there were so few cases NZ got down to zero in about 5 weeks. Once the cases numbers build up the time and economic cost to get to zero is unfeasible.

> The U.K. ranks 4th worldwide for international travellers per capita, and New Zealand 38th.

If the below is the source, you’re citing an absolute, not per capita stat. NZ ranks significantly above the UK for travel per capita, and the UK population do not travel that much.

https://www.citypopulation.de/en/world/bymap/AirTrafficPasse...

The UK is connected to continental Europe via the Channel Tunnel. We rely on an endless stream of trucks coming across from the continent and driving directly to destinations throughout the UK with their original drivers to supply us with important things like food, and they often then go on to do delivery trips within the country. (One of the big reasons that Brexit is supposed to be such a disaster is that it'll disrupt all this. With the scale at which this happens, even a small delay to each truck is apparently enough to cause massive disruption.)

Remember, this is a very good way of spreading Covid-19 to new areas - it's almost certainly how it got into Beijing, which was the best and most aggressively protected city in all of China at the time.

And yet the Chinese managed to control t. More people, higher density and little in the way of warning. It’s one hell of a failure that the UK has had. Squandered preparation time and wasted opportunity with massive economic and health/death toll costs.

Physically possible? Sure. Economically and socially possible? I think that's debatable.