A Japanese paper balloon carries bombs circa 1944-45. Thousands of the experimental weapons were sent across the Pacific during the Second World War.Courtesy of Robert Mikesh Collection, National Museum of the Pacific War Mark Bourrie’s most recent book is Big Men Fear Me: The Fast Life and Quick Death of Canada’s Most Powerful Media Mogul. The Chinese spy balloon shot down off the coast of South Carolina and the three objects of uncertain origin blown from North American skies in recent days seem like a new threat, but this isn’t the first time North Americans we have worried about strange...