The Night Wolves, Putin’s biker gang

SURROUNDED by vast wheatfields, the camouflage-painted former pig farm just outside the village of Dolna Krupa looks both incongruous and menacing. A knock on the compound’s metal gate goes unanswered, but a giant guard dog snarls back through a narrow gap. The high walls are studded with barbed wire. Small signs warn that photographs are forbidden; a larger one, somewhat implausibly, advertises the building as a “Museum”.

In June Russian state media announced that this was the “European headquarters” of the Night Wolves, a Russian motorcycle club, with whom Vladimir Putin rode in 2011. The group is banned in Poland and subject to American sanctions for its involvement in the war in eastern Ukraine. Slovakian liberals were furious over reports that the Slovak Recruits, a right-wing paramilitary group, had conducted training exercises there using old military tanks. The owner of the site, Jozef Hambalek, a politically well-connected businessman with an enthusiasm for motorcycles and nationalism...