Last week a flotilla of Russian navy vessels completed a voyage across the Arctic Ocean. The Russian Ministry of Defence has since announced that this was the first of what will be regular patrols of newly accessible shipping lanes.

The lanes are now open during the summer owing to receding sea ice, and provide a maritime shortcut between northern Asia and western Europe. Given the risk of smuggling along its lengthy Arctic coast, it is natural for Russia to want to bolster its naval presence here, says Michael Byers a specialist in international law at the University of British Columbia in Vancouver, Canada.