Angela Merkel chilled Vladimir Putin’s Kremlin this week only a few days after she dazzled the Bush White House. The back-to-back visits were an accident of scheduling. But they signal the determination of the new German chancellor to put her own stamp on the foreign policy of Europe’s strongest country.

She hopes to end three years of strained if not hostile relations between Washington and Berlin, as well as the lavish displays of camaraderie and complicity that united German and Russian leaders. Merkel is out to re-balance these key relationships – but from a new vantage point.

This is a tale of two cities reacting to the changes Merkel has begun to chart since emerging as chancellor from September’s electoral deadlock. Showing surprising toughness and skill, she put together and now directs a “grand coalition” of Germany’s two major left- and right-wing parties.

In Washington on Friday, Merkel made a point of speaking – both in public statements and privately to President Bush – of the strong “friendship” that links the two NATO allies. In Moscow on Monday, she avoided such displays of personal or rhetorical warmth. Instead Merkel spoke of “the strategic partnership” that Germany wants to maintain with Russia.

She thus reversed the visible sentiments and priorities of her predecessor, Gerhard Schroeder. That change was not lost on Putin. At their joint news conference, the Russian president called Merkel “my colleague” instead of “my friend,” the term he always used for Schroeder.

The contrast in tone that Merkel’s long weekend of diplomacy evoked in Washington and Moscow was striking. On Friday, when their staffs joined Bush and Merkel after a 40-minute one-on-one conversation, Bush emphasized to his aides that the two leaders had quickly become “George” and “Angela” to each other. Merkel was to be treated as his friend.

The changes in atmospherics will only go so far in changing substance, of course. Merkel will not alter Germany’s refusal to send troops to Iraq, and she faces huge obstacles at home to increasing defense spending, as the U.S. urges.

Moreover, she was still compelled – as she said she would be before leaving Berlin – to raise with Bush the troublesome subjects of secret CIA kidnappings and hidden prisons in Europe and the imprisonment regime at U.S. facilities in Guantanamo.

But she carefully cast her comments as the concerns of a friend who was worried about the damage being done to the U.S. image abroad – much as British Prime Minister Tony Blair has done in recent conversations with Bush, according to U.S. officials. And when the president responded with a forceful declaration that he had to take every precaution to prevent terrorist attacks on Americans, Merkel listened respectfully.

For Bush – even more than for most presidents – all politics is personal. He has told aides he could have forgiven Schroeder for opposing the U.S. invasion of Iraq, but not for allegedly misleading Bush by promising not to use Iraq as a campaign issue in Germany’s 2002 election. Schroeder used little else, and won.

Merkel’s habit of explaining big points through her own life story – a 51-year-old former East German physicist, she grew up in a communist dictatorship and came to politics only after Germany’s reunification in 1990 – also seemed likely to bond her more closely to Bush than to Putin, who served as a KGB officer in East Germany.

“She can talk to any Russian she wants to, in fluent Russian. Putin monopolized Schroeder with his KGB-taught, fluent German,” one U.S. official observed approvingly. In Moscow this week, Merkel met with citizens critical of Putin’s rule and pressed the Russian leader on the war in Chechnya.

But Merkel is not nostalgic for the Cold War or for an American protectorate over Germany that it created. She recognizes that Germany, which imports more than one-third of its energy from Russia, has to maintain a good working relationship with Putin’s country.

In an eloquent dinner speech to an enthusiastic group of American dignitaries at the German embassy here last week, Merkel tossed out an intriguing thought: At times she might be able to play “the role of a mediator” for Washington and Moscow, and “certainly not the role of someone who polarizes” relations between the two powers. She did not mention Gerhard Schroeder’s name. She did not have to.

How a mediator’s role would work is not clear. But Merkel’s clear-eyed realism about both Washington and Moscow makes her an interesting new and potentially stabilizing force of leadership in a world sorely in need of that quality.