The city's highest administrative court decided that a 59-year-old imam can be deported for threatening public security.
The cleric, a citizen of Turkey, will be sent back to his homeland. The expulsion comes amid debate in European countries about the framing of new laws and rules which deter terrorism while preserving the rights of the individual.
Brussels-based analyst Sergio Carrera, of the Centre for European Policy Studies, says this is a difficult balance to achieve, and cautions against excessive reaction.
"We cannot live in a state of fear, in which you justify any security measure or any preventive measure whatsoever, in order to curb a potential threat which might not even be real," he says.
The imam, who has not been publicly named, is being deported for statements which before the present war on terrorism would have been shrugged off as inconsequential.
At a religious gathering in Berlin last summer, he praised Arab suicide bombers in Israel and Iraq as "martyrs." In autumn, the imam was filmed by German television while delivering a sermon in which he called Germans "useless."
That was enough for the city authorities, who said his comments pose a threat to public security, and risk damaging public order. He appealed against his expulsion, but the higher court ruling against him yesterday means he must go. He has lived in Germany for more than 30 years.
But he need not feel alone. The south German state of Bavaria decided the same day to deport a Jordanian who has lived in Germany for many years under an assumed name. Authorities suspect him of being a senior member of a terrorist group.
And German officials say another 10 expulsions on terror-related grounds will take place soon.
At present, each of the 25 European Union countries decides for itself what measures to take to combat the threat of terrorism. Britain has taken probably the most far-reaching steps. The government of Prime Minister Tony Blair sought to turn into law a terrorism bill that would have made it possible for the government to detain suspects arbitrarily, without reference to a court order.
Critics said such a measure would help to undo eight centuries of constitutional development to protect the individual against royal or state power.
Analyst Christopher Langton of the International Institute of Strategic Studies in London says the debate over how far to go to control terrorism touches on some fundamental issues.
"It is an issue of the rule of law, and the rights of the individual versus what evidence there is being used indiscriminately and directly without recourse to legal process, which is the outstanding question," he says.
The bill was rejected by the British parliament's upper chamber, the House of Lords. The government then softened the bill, reinstating in a limited way the role of the courts. The measure was then passed, but on condition that it be resubmitted to parliament in one year for review.
In Brussels, Carrera says it makes sense to transfer the power to frame antiterrorist legislation to European Union authorities. He notes the open borders within the EU create a dynamic in which such an arrangement is logical.
"The Schengen agreement, which removes internal border controls in [parts of] the European Union, needs to be parallel with the development of common measures on, for example, security," Carrera says.
As a first move in this direction, a common European arrest warrant has been introduced, which allows police to arrest suspects in different EU member states. The warrant has been used about 20 times so far -- but, ironically, not yet in relation to a suspected terrorist.