But even as patience with President Vladimir V. Putin runs out, Berlin is struggling to determine how to respond. Some have suggested canceling the Nord Stream 2 pipeline, a near-completed $ 11 billion project to transport natural gas from Russia to Germany. So far, however, the German government, its European allies and the United States have taken no action other than the prospect of further sanctions against Russia.
The poisoning of Mr. Navalny is the latest in a long series of assassinations or attempted assassinations of opponents in the Kremlin in recent years. On August 20, after campaigning in Siberia for anti-government candidates for local offices, he collapsed, was hospitalized and airlifted to Germany for treatment two days later.
Local elections were held across Russia over the weekend, and Mr. Navalny and his allies made modest gains. In the biggest opposition victory, Mr. Putin’s United Russia party lost its majority on the city council of Novosibirsk, a Siberian industrial hub and Russia’s third largest city.
The attack on Mr. Navalny increases the pressure on the close, complicated and increasingly contradictory German-Russian relationship.
Chancellor Angela Merkel was unusually clear in her harsh condemnation of Moscow cheeky actions and lack of cooperation. Less than a year ago, a former Chechen rebel leader was assassinated in broad daylight in a Berlin park, a murder which German federal prosecutors say was orchestrated by the Russian state.
Ms Merkel, who normally speaks with Mr Putin by phone at least once a week, has not spoken to him since Mr Navalny was poisoned, a senior German security official said. On Monday, Russian Foreign Minister Sergei V. Lavrov canceled a meeting scheduled this week with his German counterpart, Heiko Maas. In a statement, the Russian Foreign Ministry did not mention the poisoning of Navalny and said the cancellation was related to a scheduling conflict.