Swedish families have this week received an ominous yellow leaflet. The cover shows an illustration of a female soldier with an assault rifle. In big black letters it says: “If crisis or war comes”.

The leaflet contains information on everything from how to deal with anxiety, how to staunch a bleeding wound and what to do if an air raid alarm sounds.

It also urges inhabitants to keep enough cash on hand for a week of essentials “preferably in different denominations” and to “use cash occasionally”.

The Swedish Civil Contingencies Agency, which is behind the brochure, says it will increase citizens’ “emergency preparedness”. Norway, Finland and Denmark have published similar guidance in recent months.

It is a significant shift for a group of countries that were on the cusp of going totally cashless.

Russia’s invasion of Ukraine has brought the threat of cyber attacks, sabotage and outright war closer to home in the Nordics. Payments networks could be a potential target.