BERLIN — Germans sleep better, Bismarck once said, when they don’t know how sausages and laws are made.

A century and a half later, Chancellor Angela Merkel seems to be modeling an election campaign on the musings of Bismarck, the “Iron Chancellor.” She is avoiding detailed discussion of what she would do with a third term, emphasizing instead her personal appeal over policy prescriptions.

In five weeks, Germans will vote in what has been billed as the most important election of the year in Europe, a continent struggling to emerge from years of financial and economic crisis. Yet there is virtually no debate about the major problems facing Germany — like handling its departure from nuclear energy, the aging of its population and articulating a vision for the euro zone.

Differences between the major parties are also hard to identify. Ms. Merkel has pushed her Christian Democrats so close to the opposition Social Democrats and Greens on energy, wages and family policy that the parties have become virtually indistinguishable for many voters.