Nearly seven years ago the then justice secretary took a ferry to Arran, the island dubbed “Scotland in miniature”. Kenny MacAskill was thinking of merging the country’s eight old territorial polices and national crime agency in to a single new service.

The minister wanted to hear what islanders - whose needs were very different to those of most of the old Strathclyde police - had to say about the idea. So, over tea and home-made scones, Mr MacAskill quizzed some pensioners at a Lamlash kirk coffee morning. They responded with a question of their own: “Will Sergeant Mackay still be in charge?”.

All policing is local. It begin local and it ends local. A crime can be part of a global conspiracy, an internationally inspired terror act or a transnational credit card scam. But the victims and the perpetrators are alway local to somewhere. The same thing applies to a car accident or a missing person.

It was no surprise, therefore, that Lamlash pensioners were more bothered about who their local sergrant was rather than whether their chief constable had his office in Glasgow, Edinburgh or Tulliallan Castle.

Mr MacAskill was later to sign off on a national force - harried by opposition politicians eager for the efficiencies and savings such a body was to bring.

Some of those advantages, as it happens, were underlined on Tuesday when senior officers revealed a fall in homicide numbers in the first half of this year.

They underlined an important detail: every single killing was solved, thanks to national murder investigation teams that are as sharp in Lamlash as they are in Leith. But equally those teams - like national units countering terrorism or organised crime - cannot work without local cops with local knowledge.

All policing is still local. But all policing politics is now national. Yesterday Scotland’s acting police chief admitted times were challenging for his services.

But he also stressed police forces, if not his own, had faced similar issues before. Police Scotland, he might have added, has problems. But they are far from unprecedented.

What is new is the sheer intensity of post-indyref politics.

Back in 2011, on the ferry to Arran, MacAskill flicked through papers suggesting, for the first time, an SNP landslide and a referendum. It was that big vote, as much as police reform itself, which was to define the politics of the national force.