President Obama is hosting German Chancellor Angela Merkel today. Herrzlich Wilkommen in Washington! Despite past differences over Libya, economic policy and lots of other stuff, the two leaders are doing their utmost to project warmth and unity. Obama draped the Medal of Freedom around Frau Merkel’s neck, and told the Berlin newspaper Der Tagesspiegel that he trusts her “when she makes a commitment.” 

No doubt that’s true for the commitments she has made to the U.S. But what about some of the promises she has made to Germany? Specifically, her recent decision to end nuclear power in Germany by 2022 — contrary to her previous decision, in fulfillment of a 2009 campaign pledge, to extend the life of 17 German nukes beyond that date — has to be one of the most blatant political flip-flops of all time. 

Here’s the backstory. Running for re-election two years ago, Merkel promised to undo a law, passed in 2002 by the previous center-left coalition, that would have phased out all nuclear energy in Germany by 2021. To be sure, during her first term from 2005 to 2009, in which she and the center-left Social Democrats ruled as an uneasy coalition, Merkel left that law undisturbed. But, courting more pro-business coalition partners in 2009, she argued that nuclear power was safe and economically necessary, and would help eliminate greenhouse gases. "We urgently need to keep the plants up and running for longer," she said. Just eight months ago, the German parliament, dominated by Merkel’s coalition, passed a law extending the life of the country’s nukes by 12 years.

Every country has its national quirks, and one of Germany’s is a fear of nuclear energy. It may seem odd in the nation whose scientists gave us the X-ray and quantum physics – and that elected a physicist, Angela Merkel, as its leader. But, despite the unblemished safety record at German nuclear plants, the country’s Green movement opposes this carbon-free form of energy with the same fervor that the National Rifle Association opposes gun control. And most Germans tend to agree.  

After the accident at Fukushima, Japan, anti-nuclear sentiment spiked in Germany, costing Merkel’s party a majority in prosperous Baden-Wurtemberg state for the first time since World War II. No matter that the German reactors which provide 23 percent of the country’s electricity are of a different design than those in Japan, or that the possibility of an earthquake, let alone a tsunami, in Germany is essentially nil.  

Merkel promptly put herself at the head of the anti-nuclear movement. The great German sociologist Max Weber defined political leadership as the capacity to declare, with the same passion that Martin Luther once exhibited, “Here I stand; I can do no other.” Merkel seems to have amended that to read: “Here I stand, but I could move if you want.” 

Or has she? I have been trying to understand why Merkel would do something that probably goes against her policy views and scientific training, that makes no sense environmentally (since it will lead to a short-term increase in carbon-belching coal-generated electric power), and that could do major long-term damage to the German economy. The conclusion I come to is that she’s betting a total ban on nuclear power in Germany will never actually occur; or at least that won’t go into effect as early as 2022.  

Yes, Germans tell pollsters now that they’d be willing to pay a bit extra on their electric bills to get rid of nukes. But few of them have any idea what it’s really going to cost — not just in higher household bills, but lost jobs and competitiveness in German industry — to replace nearly a quarter of the nation’s electric-power capacity in a little more than a decade. A recent J.P. Morgan analysis notes that solar, wind and hydroelectric can only fill part of the gap, and even that will require “massive grid infrastructure investment.” 

Merkel knows this. She also knows that, having flip-flopped on this issue once, she, or some future government, can flip-flop again between now and 2022 — when and if the German public finally figures out what it’s really going to cost to indulge their fears.

In the meantime, she has more pressing business – in particular, salvaging the Euro, and the European Union on which it depends. Avoiding a fight over nukes preserves her political strength for that larger and more immediate battle. Weber himself said that passion is a necessity in politics — but must always be tempered by “a sense of proportion.” And for Merkel, nothing matters more right now than dealing with the European crisis, from the strongest political position that she and her coalition can possibly maintain.