A group of advisers chartered by the Army has privately pointed out to senior leaders what many insiders might shrug off as a sad piece of common knowledge: that the service has an abysmal record of pumping billions of dollars into weapon systems that will never be deployed, with the trend of sunk costs pointing upward during the past decade, Inside the Army has learned. Canceled programs have eaten up between $3.3 billion and $3.8 billion per year since...