First let’s get the headline out of the way which prompted the latest stage of the diplomatic crisis between Germany and Turkey. The Turks have arrested another half dozen human rights activists from foreign countries this week, charging them with “having connections” to terror groups. (This is the same excuse they use for virtually anyone that President Recep Tayyip Erdogan views as a political dissident.) In one sweeping move, Erdogan has managed to enrage multiple additional countries. (Deutsche Welle)

Six people, including German human rights consultant Peter Steudtner and Amnesty International’s director for Turkey, Idil Eser, are to remain in custody awaiting trial for allegedly aiding a terror group. Pre-trial detention in Turkey can last for up to five years.

“Six were remanded in custody and four released on judicial control” by a Turkish court on Tuesday, Amnesty International’s Turkey researcher Andrew Gardner said. Steudtner was reported to be receiving German consular support while in custody.

German Chancellor Angela Merkel condemned Steudtner’s detention, saying it was “absolutely unjustified.”

Sadly, this bit of news is almost too common to bother mentioning these days because Erdogan has been imprisoning people by the tens of thousands for months now. Of course, when Germany pushed back after these latest arrests it set of a war of words between Ankara and Berlin. Turkey’s Foreign Ministry responded to demands for the release of Steudtner by saying they were “unacceptable” and that “the independent Turkish judiciary must be trusted.” (Demanding that Erdogan’s regime be “trusted” for pretty much anything these days is laughable, but I suppose we have to keep of the pretense of diplomacy.)

But what’s really interesting and may provide a template for other countries when dealing with the Tyrant of Turkey is Germany’s next response. Their Foreign Minister has announced instructions to German citizens officially warning them about travel to that country.

Germany on Thursday told all citizens traveling to Turkey to exercise caution following the jailing of a human rights activist who had no previous links to the country, which Germany’s foreign minister said shows that “every German citizen in Turkey” could suffer the same fate.

Foreign Minister Sigmar Gabriel said he also can’t see how the German government can continue to guarantee German companies’ investments in Turkey in light of the threat of “arbitrary expropriations for political reasons.”

He added that Berlin will talk with its European Union partners about the future of pre-accession financial aid for Ankara, which is in slow-moving talks to join the bloc.

The German government will consider those questions and “further measures” over the coming weeks, Gabriel said.

This is actually kind of brilliant. Many countries, including the United States, have been struggling with the question of what to do about Turkey. Given their critical geopolitical position in the war on terror and the refugee crisis in Europe, nobody seems to want to swat them down too harshly. Any huge sanctions package such as the ones which have been employed against Russia and Venezuela would no doubt prompt a significant backlash from Erdogan in response. But what if there’s something short of that?

We might actually be able to nudge Erdogan toward at least a bit better behavior if enough countries followed this blueprint. Rather than quarantining the country entirely, issuing a “travel advisory” along with statements that we can’t guarantee the safety and security of anyone going to Turkey would no doubt dampen the flow of travelers. The tourism industry in Turkey took a huge hit after the coup, but as Bloomberg reported earlier this year they’ve finally made a comeback. It’s a significant part of their economy. If most of the west began issuing travel advisories the way the Germans are we could put the squeeze on Erdogan’s economy without having to resort to official sanctions.

The second half of the German formula also looks like a winner. They won’t forbid any businesses from operating in or dealing with Turkey, but they’re going to refuse to guarantee German companies’ investments there. If foreign businesses are being told that their governments won’t back their investments, that revenue stream likely begins to dry up also.

If a few clever leaders (memo to POTUS) got together quietly and and had their State Departments issue similar advisories, Erdogan would begin to feel seriously isolated without having any overt governmental action taken against him. Hit him in the wallet and we might elicit a better response than the normal diplomatic carrot and stick approach has been producing thus far. It’s at least worth trying.