The case drew widespread attention in Europe. The cables show that the United States was especially concerned about cooperation between Spanish and German prosecutors. The Spanish courts became involved because they concluded that the plane that transported Mr. Masri had traveled through Spanish territory.

“This coordination among independent investigators will complicate our efforts to manage this case at a discreet government-to-government level,” read a cable sent from the embassy in Madrid in January 2007.

The cables’ release has created a stir in Germany mostly because the documents contain American diplomats’ caustic comments about German officials and because they show that the embassy had informants in one of the governing parties. The Masri case, however, has already been so thoroughly discussed in public, and the degree of Washington’s pressure on Berlin is so well known, that it has not gained much attention.

The one cable that has caught the attention of some in the German press was written on Feb. 6, 2007, by Mr. Koenig, the second-highest-ranking diplomat in the embassy, under the title “CHANCELLERY AWARE OF USG CONCERNS.”

Rolf Nikel, Germany’s deputy national security adviser, told Mr. Koenig that the two governments had differences over Washington’s antiterrorism methods, including German opposition to the prison at Guantánamo Bay, Cuba, and to rendition. Mr. Nikel said, according to the cable, “the Chancellery is well aware of the bilateral political implications of the case, but added that this case ‘will not be easy,’ because of the intense pressure from the parliament and the German media.”

Mr. Koenig said that while Washington “recognized the independence of the German judiciary,” he added that “to issue international arrest warrants or extradition requests would require the concurrence of the German Federal Government.”

His point was that the case could be stopped.

The prosecutor’s office in Munich issued warrants for the arrest of the C.I.A. operatives, but Germany’s government did not press for arrests or extraditions.

“We already dealt with this, including in the Bundestag, about why the German federal government did not take further action to carry out the arrest warrant,” said Mr. Ströbele. “How one deals with the fact that he was taken into custody and tortured  whether more will be revealed on that  what was done in order to keep it a secret: that is what interests me.”