In what could prove a watershed moment in her long political career, Angela Merkel is playing go-between this week with two angry superpowers while trying to deliver peace to a European continent terrified that the Ukraine conflict could expand into an all-out, east-west war with Russia. She faces a daunting and potentially thankless task.
The German chancellor has emerged as Europe's lone champion in the dread-filled months following Vladimir Putin's calm-shattering invasion and annexation of Crimea almost one year ago. In part through her dozens of one-to-one telephone conversations with Russia's bellicose president, in part because of Germany's unmatched trade and energy ties with the country and in part because others have failed to step up, Merkel has come to be viewed as Europe's foremost Ukraine mediator, conduit and fixer. When she travelled to Moscow to see Putin last Friday, the fact that François Hollande, the French president, accompanied her was all but irrelevant. Hollande's is merely a walk-on part. His presence at the table strengthened Merkel's mandate as de facto spokesperson for the EU, but added little to her leverage with Putin.
Britain, which like France clings vainly to its self-perception as a European heavy-hitter on defence and security matters, has been even less involved. Perhaps David Cameron, fixated on the May general election, calculates that there are no votes in Ukraine. Be that as it may, Britain has been reduced to unhelpfully shouting insults from the touchline, as the foreign secretary, Philip Hammond, did in his weekend tirade about Putin the 'tyrant'.
The loneliness of Merkel's long-distance mission has become desperately clear in recent days. She is assailed from all sides, by friends and enemies alike. It is an experience another prominent European powerbroker and her distant predecessor, Otto von Bismarck, might have found familiar.
On the one hand, Russia continues to look both ways, Janus-like. Having encouraged hopes that a new Ukraine ceasefire and settlement was within reach, Putin quickly moved after Friday's talks to warn that the follow-up summit agreed for Minsk on Wednesday was contingent on key issues being settled in advance. Senior officials from all parties scrambled to Berlin on Monday to try to fulfil that demand.
On a visit to Egypt - in part to demonstrate that his is not internationally isolated - Putin regurgitated his familiar grievances about the west trying to encircle and crush Russia, and Nato breaking its promise not to expand up to the country's borders. "We repeatedly warned the US and its western allies about harmful consequences of their interference in Ukrainian domestic affairs, but they did not listen to our opinion," he said. This did not sound like a man about to sign an historic peace deal.
On the other hand, Merkel has to deal with the growing, slightly simplistic conviction in Washington that the only way to get Putin to back off is to supply state-of-the-art defensive weapons to the Ukrainian government, an option Merkel - like most EU leaders - firmly believes would make matters worse. Barack Obama, with whom she discussed the idea at a White House meeting on Monday, is expected to delay a decision pending the outcome in Minsk.
Joe Biden, his vice-president, has hinted, however, that US restraint may not be long-lived. "Given Russia's recent history, we need to judge its deeds not its words. Don't tell us, show us, President Putin," he said at the weekend. The Ukrainians "have a right to defend themselves".
Congressional hardliners have gone much further. They suggest Merkel's diplomacy has unwittingly provided cover for continued Russian misbehaviour, mendacity and land-grabs. Russia ignored last September's Minsk ceasefire accord, upon which Merkel is basing the current negotiations, almost from day one, her US critics argue. So why believe the outcome will be any different now? According to Bild newspaper, US delegates to the weekend Munich security conference accused her of appeasement and described the peace talks as "Moscow bullshit".
For the Republican right and its media allies, Merkel is naive, or worse, a defeatist. According to reports, Senator John McCain compared her initiative to the 1938 Munich agreement between Neville Chamberlain and Adolf Hitler. "History shows us that dictators will always take more if you let them," McCain was quoted as saying in Munich. "They will not be dissuaded from their brutal behaviour when you fly to meet them to Moscow - just as leaders once flew to this city."
Pressed on both flanks, Merkel is also under attack from fellow EU members and those she is trying to help. East European states such as Estonia and Poland are particularly exercised about the potential threat, and are keen to see the US and Nato take a bigger, more active role in curbing Russian aggression. The Ukrainian government also worries that any deal with Putin, particularly over a proposed buffer zone embracing the current frontlines and the previous ceasefire line, will force Kiev to cede yet more territory to the separatists, possibly in perpetuity.
Given these many conflicting demands, Merkel could end up satisfying no one this week, either with a peace accord that is undermined and disregarded before the ink is dry or with no accord at all. If she does manage to pull off a lasting deal, however, the comparison with Bismarck may not be an idle one.