Germany has urged its citizens not to travel to Turkey and advised companies to scale back their investments in the country.

The dramatic measures follow Turkey’s arrest of a German human-rights activist, Peter Steudtner. But relations between the NATO allies have been going downhill for years.

• German chancellor Angela Merkel offended her Turkish counterpart, Recep Tayyip Erdoğan, in 2005, when she declared her opposition to Turkish membership of the EU.
• Germany has for years complained about Turkish attempts to influence its three to four million citizens of Turkish descent.
• Earlier this year, Erdoğan called German officials Nazis when they would not allow his surrogates to campaign for him in Germany.
• Turkey refused to give German lawmakers access to the Incirlik Air Base, where their troops fighting the Islamic State were based. Germany eventually moved its forces to Jordan.
• Turkey arrested a German-Turkish journalist, Deniz Yücel, after he had written critical articles about Erdoğan. Yücel is still being held in solitary confinement.

“We have no choice”

Foreign Minister Sigmar Gabriel told reporters on Thursday that 22 German nationals have been detained in Turkey since a military coup against Erdoğan failed last year. Nine remain in custody.

“We have been very patient, even if it wasn’t that easy,” Gabriel said. “We have no choice.”

He also referenced Erdoğan’s dictatorial behavior and Turkey’s retreat from liberal Western values as reasons for scaling back the relationship.

Economic damage

The sanctions could do real damage.

• Tourism accounts for nearly 15 percent of Turkey’s economy. Germans comprise the largest group of tourists. 5.5 million visited Turkey in 2015.
• Almost 7,000 German companies operate in Turkey and they are some of the country’s largest investors.
• Germany is Turkey’s largest export market.

Germany is also expected to ask the EU to suspend €5 billion in aid to Ankara.