The way Nicola Sturgeon sees it, there is no way to know for sure how far the Covid variants are spreading or whether new mutations could arise in different parts of the world then reach our shores.
Focusing only on the red list is, the Scottish First Minister believes, not sufficient to keep people safe.
That’s why Scotland is now making all intentional arrivals (with a few well documented exemptions) quarantine for 10 days on arrival.
However, there is a loophole.
Travellers coming to Scotland know they will face 10 days of quarantine in a hotel at a cost of £1,750 for a single adult. They also know if they’re not coming from a red list country, they could avoid that by travelling into England instead, then making their way to Scotland by plane, train, or automobile.
There are no checks on the Scotland-England border.
It is quite a lot of effort to go to, though. So would anyone really do that just to skip quarantine?
Well, put it this way: there were meant to be 65 arrivals from Istanbul in Edinburgh today. Instead, only four made the journey.
What happened to the other 61?
We have no idea at this stage. But we do know they could avoid paying £1,750 by transferring onto an Istanbul to London flight tomorrow - at a cost of roughly £700.
From there, with £1,000 in their pocket, they could make their way to Scotland. Officially they are supposed to then quarantine voluntarily but nobody is checking and it would be near impossible to track under the current system.
The cost of quarantine for a family could be enough of an incentive for travellers to get creative.
There is a gaping hole in the net and Nicola Sturgeon is asking the UK Government to work with her to close it. After all, it’s in no one’s interests to have international travellers crossing England on public transport carrying who-knows-what variant with them.