The resignation of Hiroto Saikawa, chief executive of Nissan Motor Co. gives the embattled Japanese carmaker a much needed opportunity to clean decks and move on.

Ever since the shock arrest of the company's chairman Carlos Ghosn almost a year ago, the Japanese auto giant has been in permanent crisis mode and ties with its French alliance partner Renault SA have frayed. To steer it through that period Nissan needed a leader with deft political skills who embodied a clean break with the Ghosn era. Saikawa — a Ghosn appointee — wasn't it.

The report that Nissan published concurrently on Monday, detailing allegations of financial misconduct by Ghosn, makes for grim reading (Ghosn denies wrongdoing). Yet Saikawa could never distance himself fully from an era during which Nissan paid lip service to principles of good corporate governance.