More non-news on the Russia-collusion front came Wednesday, when the Senate Intelligence Committee said it has now verified what everyone knew nine months ago: Russia worked to sow chaos during the 2016 election; vote totals weren’t affected; and no evidence has emerged that Donald Trump was in cahoots with Moscow.

But in the more distant, less camera-filled corners of Washington, there actually is some interesting new information. It centers on the document that increasingly looks central to the “chaos” Russia sowed: the...