The European Union may be about to make a bad mistake in calling off Turkish membership talks that were due to re-start this week, after three years in the deep freeze.

The move is led by Germany's Chancellor Angela Merkel, who has long opposed admitting Turkey and says she is "appalled" by the way in which its government has handled the protests that erupted in Istanbul at the end of May. Well, we should all be appalled by Prime Minister Recep Tayyip Erdogan's crackdown, but Germany's move will make things worse.

On Friday, the two countries summoned each other's ambassadors to lodge formal complaints about the rhetoric from the other. A day earlier, Germany had blocked approval for the planned opening of talks on Turkey's EU bid, on regional policies.

Turkey may never join the EU. Croatia, which became an EU candidate at the same time as Turkey, in 2004, completed negotiations in 2011 and will become a member on July 1. Turkey, meanwhile, has closed just one of the 35 negotiating chapters, mainly due to blocking actions by Cyprus, France and Germany.

Even so, Turkey's membership aspirations have been central to several improvements in rights and freedoms that made the recent Gezi Park protests possible. Just to become a candidate, Turkey had to make big changes, such as abolishing the death penalty. If Merkel is truly concerned about human rights in Turkey, she should accelerate the accession process rather than block it. The logical thing to do is to expand the talks to the areas where Turkey needs to improve most, such as justice and fundamental rights; freedom and security; education and culture; and taxation.

Erdogan continues to demonize the protesters and encourage division in an already polarized society. He has promised retribution against his political opponents in the business community, and indulged in unlikely conspiracy theories involving everyone from CNN International to Twitter to what he calls the "interest-rate lobby."

What makes this ever-escalating rhetoric dangerous is that he is surrounded by "yes" men, who are all too willing to turn his threats into reality. To pick the most egregious example, Erdogan has branded the protesters terrorists. The cabinet minister in charge of Turkey's bid to join the European Union, Egemen Bagis, followed up by declaring that any protester approaching Istanbul's Taksim Square would be considered a member of a terrorist organization. Apart from being ridiculous (how can you define terrorism as trying to go to a public square?), this has especially severe implications in Turkey, where terrorism charges are prosecuted by separate courts and prosecutors, and defendants are subject to almost unlimited detention.

When the European Parliament criticized the Turkish police for its handling of the protests, Erdogan thundered that he didn't recognize the parliament. Bagis lashed out at Germany, accusing Merkel of using Turkey as a campaign issue ahead of September's elections and threatening that Turkey might cut off relations with the EU if next week's negotiating round didn't go ahead.

The EU doesn't need this fight, nor does Turkey. Germany's killing of the talks would achieve the opposite of what's intended, hurting most of all the pro-Western, Twitter-savvy 20-somethings who are demanding their rights. There is still time before Wednesday's scheduled restart for Germany to do the smart thing.

(Marc Champion is a member of Bloomberg View's editorial board. Follow him on Twitter.)