“It must be possible to work through a historical event that took place 100 years ago,” he added.

But Aydan Ozoguz, the government’s commissioner for integration, said that while she would vote for the resolution, “I still think it is the wrong path” and that it will backfire.

Mr. Erdogan and ultranationalist Turks “will get a huge boost,” Ms. Ozoguz said this week.

“They will use the resolution as proof of a further attack by the West on Turkey,” she said. “Reasonable, considered voices will be isolated and will have no chance to be heard for a long time.”

Mr. Ozdemir, though, argued that the resolution would not be to blame for limiting or stopping historical investigation, since Mr. Erdogan has already “intervened expressly” to squelch any such moves.

The Green leader has also been critical of Ms. Merkel, accusing her of paying little heed to Turkey for most of her decade in power and now being forced to deal with Mr. Erdogan.

Increasingly, the chancellor has engaged in a balancing act. When she visited Istanbul for a United Nations summit meeting last week, she spent time with Turkish intellectuals and lawyers critical of Mr. Erdogan before meeting the president.

After a German comic lampooned Mr. Erdogan with a crude poem, Ms. Merkel initially criticized the verses, giving the impression — which she later said was a mistake — that she advocated curbing the freedom of satire in Germany.

The Armenian resolution has illustrated the many sensitivities of dealing with Turkey. Mr. Ozdemir said that Ms. Merkel and her foreign minister, Mr. Steinmeier, had pushed last spring to postpone the vote on it. That was before the migrant crisis, when ties between Germany and Turkey were less complicated.