Sweden has always had a problem with Russians and the sea. You can see why when you visit the Stockholm Archipelago and learn about the days when whole islands were set on fire by Russian invadersin the 18th century. Covered with fir trees and little wooden houses, they are very combustible. Whole towns were burned down. It was called a ‘terror’ campaign. Against this, Sweden’s easterndefences are not too impressive. The story is told of the Prussian general Helmuth von Moltke that he laughed ‘only twice in his life: once when he heard of the death of his mother-in-law, and thenwhen he visited Waxholm.’ Waxholm fort was supposed to be Stockholm’s outer defence.

Russophobia (ryss skräck) has been a constant in Swedish history. Children used to be warned that the Russians would come and get them if they didn’t behave. During the Cold War there werefrequent scares about Russian submarines snooping among the islands, the biggest of which led to a full-scale diplomatic crisis in October 1981. A Soviet sub armed with nuclear weapons was groundednear Karlskrona, a Swedish naval base. The Russians claimed it had lost its way; the Swedish military suspected it was part of more widespread and implicitly hostile Soviet surveillance of theSwedish coast. Some subsequent sightings have undoubtedly been genuine, but others turned out to be mistaken. According to Ola Tunander, in The Secret War Against Sweden: US and BritishSubmarine Deception in the 1980s (2004), many of them were set up by Britain and America to persuade the Swedes to join Nato. The Liberals, the most pro-Nato party in Sweden, are exploitingthis recent incident to the same end. There was already plenty of anti-Putin feeling over Ukraine, as well as dislike of Russian authoritarianism and fears for the Baltic States.

What the truth of it is we don’t know yet. The only picture circulating in the Swedish press, an amateur photograph purporting to show the submarine, has a Loch Ness Monster look about it. Early onpeople were sceptical; but cumulative evidence from the military authorities, experts and researchers, and from the secret services, has now persuaded most people that there actually are one ormore submarines – or maybe minisubs – in the Archipelago that shouldn’t be there, and that they are indeed Russian. As a result there has been a massive navy operation – the biggest in Sweden sincethe Cold War – to discover, and then to stop, chase or follow the submarine(s). There has been huge media coverage almost every minute of the day, with people going out in private boats to catch aglimpse of the mysterious sub. We’re all very excited. Yesterday’s Dagens Nyheter had a map showing its probable route from Nämdö, where it was first spotted on Friday, past ‘our’ island(we have a sommarhus on Svartsö), and south into the open Baltic. The latest rumour is that the Swedish military is going to let it get away. We’ll see.

Most of the attention has been on the chase itself, less on the Russians’ motives. They are difficult to fathom, which is one reason people were reluctant to believe the whole thing. What do theRussians want from us? (Surely not our wonderful parental leave?) Do they plan to invade? (In 2013 Russian bombers were spotted flying over Stockholm and southern Sweden.) It seems unlikely.Another theory is that the Russians want to scare us, after the Social Democratic/Green victory in the recent election, out of joining Nato. Or is it simply a silly game of cat and mouse?

On the Swedish side, do the military genuinely believe in this new Russian threat, or is it simply a ruse to increase defence spending? After the end of the Cold War there was a longish period ofseeming rapprochement with Russia. The idea of a strong military became more and more redundant. Expenditure on the army and navy fell sharply. This may be changing now, in response to these eventsin the beautiful Archipelago. The old ryss skräck is returning.