Germany's first female chancellor has been accused of placating Russian President Vladimir Putin in the name of realpolitik, while deepening Germany's dependence on Moscow - not least by backing the Nord Stream 2 gas pipeline project even after Russia annexation of Crimea in 2014.
Hedwig Richter, modern history professor at Munich's Bundeswehr University, said Merkel's loss of standing had been exceptional, representing a generation of political failings.
Richter told AFP that amorality is not the same as realpolitik.
The governments of the last 16 years thought it was realistic to place values such as human rights and climate protection last in politics. Reality is striking back. Ukrainian President Volodymyr Zelenskyy blamed Merkel's feet for a decision at the NATO summit in Bucharest in 2008 not to admit his country to the alliance.
In April, he offered her a barbed invitation to Bucha, the site of an alleged massacre of Ukrainian civilians, to see what the policy of concessions to Russia has led to in the past 14 years. Looming energy shortages due to Russian retaliation for Western sanctions have also soured the mood against Merkel at home.
Nico Fried, who covered Merkel during all four of her terms, said in Stern magazine that Merkel was tied up with this war and certainly to blame for the missing gas.
What remains of Merkel after 16 years, or whether her historical portrait is already fading before it is framed? According to a Civey institute poll in late November, just 23 per cent of Germans would want Merkel back in power.
Richter said that Merkel had great achievements including allowing more than one million asylum seekers and standing as a beacon of decency and democratic duty when strongmen like Putin and Donald Trump were on the march.
She said two key miscalculations would cast a long shadow.
She said because of the close relationship between Russia and fossil fuels, it threw a spotlight on the destruction of the planet.
Both the Merkel and the Clinton governments have neglected both of these issues. Merkel, 68, has mounted a tentative counter-offensive, arguing that she acted in good conscience given the facts on the ground at the time.
She tried to use Nord Stream 2 as a bargaining chip to make sure Putin adheres to the Minsk accords of 2015 aimed at stopping the fighting in Ukraine.
Merkel told Fried that if Russia invaded Ukraine, the pipeline deal would be scrapped - a threat that her successor Olaf Scholz made good on days before the war began, as she promised to US President Joe Biden last year.
Osang pointed out that Putin of all people, whom she has known so well and long, had muddied his reputation with all his tricks, lies.
Osang said this influenced her approach to trade with China and energy deals with Russia.
She said Scholz's billions of dollars were justified in spending to help Germans facing high gas prices.
She said not everyone is in a position to freeze for Ukraine.