BERLIN — He was skinny in his trim, dark suit, an almost lupine figure, nervous and unexpectedly youthful for a president of Russia. Taking the lectern beneath the dome of the restored Reichstag, Vladimir V. Putin soon shifted to German, with a fluency that startled the German lawmakers and a pro-West message that reassured them. The Cold War seemed over.

It was 2001, just weeks after the Sept. 11 attacks, and Mr. Putin pledged solidarity with America while also sketching a vision of Russia’s European destiny. He was the first Russian leader to address the German Parliament, and lawmakers jumped to their feet, applauding, as many deputies marveled that he could speak their language so well.

Except for Angela Merkel, then the relatively untested leader of the opposition. She joined the standing ovation but turned to say something to a lawmaker who had grown up in the formerly Communist East, as she had. She knew how Mr. Putin’s German had gotten so good.

“Thanks to the Stasi,” Ms. Merkel said, a reference to the East German secret police Mr. Putin had worked alongside when he was a young K.G.B. officer in Dresden.