Truth has long since been co-opted as a weapon of war.

That's Peter Kosminsky, talking about his recent drama, the promise. That might seem just a restatement of the weary cliche about truth being a casualty, but it's not. Truth as a weapon makes it something altogether less passive: not a victim, but something living, breathing and potentially lethal. A thing one needs to learn to understand to gain any chance of protection from it.