S HE IS STILL Germany’s chancellor. But, after 13 sober and admirable years at the top, Angela Merkel’s authority has melted away. On October 29th, following an astonishing drubbing handed out to her Christian Democratic Union ( CDU ) in the prosperous state of Hesse, she announced that she will step down as leader of the party in December. In theory, she could remain as chancellor until 2021. But, as she herself remarked about her predecessor, Gerhard Schröder, who tried to buy himself time with a similar manoeuvre back in 2004, the two jobs belong together.

Her position now is even worse than his was then. Mrs Merkel’s writ does not run in her own party, which recently ousted a close ally from his position as parliamentary leader in the Bundestag. Worse, her coalition with the Social Democrats ( SPD ), who were also walloped in Hesse, is at risk of collapse. Even if the SPD do not walk out in the coming days, the two parties now so thoroughly dislike each other that she will struggle to govern. Mr Schröder lasted only 15 months after leaving his party job before being forced to call an early election, which he lost. Mrs Merkel should not expect to last any longer.

The timing could hardly be worse (see article). The EU is being buffeted by Brexit and the threat of an Italian-inspired euro crisis. President Donald Trump is forcing Europe to rethink its security. When leadership is required, neither the EU nor the world should welcome a prolonged period of Teutonic paralysis. Quite possibly, the pace will be forced by the SPD ’s departure from the coalition. Mrs Merkel also said this week that she will not fight another election and she is unlikely to stay on as head of a new coalition or a minority government. As the lamest of ducks, she will struggle to achieve anything.

Even if the “grand coalition” staggers on, Mrs Merkel should not hang around for long. The CDU , when it gathers in December at the congress that will now choose a new party leader, will be aware that it is also choosing the probable next chancellor, which is why three powerful candidates jumped into the frame on the day she made her announcement. Others are likely to follow. The winner will instantly upstage the incumbent.

As well as being speedy, the process needs to be transparent. On migration policy, euro-zone reforms and defence, the CDU has large disagreements that need to be hammered out. The choice of a successor to Mrs Merkel is the time to do it. There should thus be a genuine debate about principles and, above all, no attempt by Mrs Merkel to push forward the successor who would be the most likely to prop her up.

So far she has not entirely lived up to that ideal. It is widely understood that she wants Annegret Kramp-Karrenbauer to take over (she nominated “ AKK ” to the post of party general secretary in February with just that in mind, many believe). Ms Kramp-Karrenbauer, as far as one can tell, shares most of Mrs Merkel’s centrist instincts. The other two declared contenders, Jens Spahn and Friedrich Merz, are considerably further to the right. Either of them might help the CDU stem the haemorrhage of votes to the Alternative for Germany ( A f D ), but would alienate the Social Democrats, assuming they remain in the coalition that long.