evidence: There may have been more daring capers, but one recently retired U.S. military commander, a man who has held senior appointments and is knowledgeable about the Baltic region, couldn’t help but acknowledge what he called the "coolness factor" of the Nord Stream attack. Cool, because whoever did it managed to achieve total surprise and leave few traces behind. Indeed, more than a year later, nobody knows for certain who was responsible, although accumulating evidence has begun to point in a specific direction. Officials from Sweden, Denmark, and Germany would answer none of my questions. Nor would officials at the White House, the Office of the Director of National Intelligence, or the Pentagon comment on the record, beyond denouncing the act as sabotage. Sweden, Denmark, and Germany have initiated criminal investigations, but very little has emerged about the conduct of any of these probes. That has surprised some journalists, who are used to a leakier status quo. None of the relevant investigating authorities has announced a clear finish line, although Swedish officials have expressed the hope that a decision on whether to bring charges could be made by the end of the year.