German Finance Minister Wolfgang Schäuble said last month that a British exit from the European Union would be “a poison” to the British and global economies. (Markus Schreiber/AP)

The Germans are not known for emoting, and the country’s famously flinty finance minister, Wolfgang Schäuble, is no exception.

But when Schäuble was recently asked what Germany would do if Britain voted to leave the European Union, he couldn’t help baring his soul.

“We would cry,” the 73-year-old politician said.

The comment drew laughs. But for Germany, the increasingly lonely-at-the-top power behind the European Union, it also reflected a genuine sense that the country has almost as much at stake when Britain votes on the issue June 23 as Britain does. In the view of Schäuble and other top German policymakers, a British exit could be disastrous — for Germany and for the vision of an integrated Europe that Berlin has steadfastly sought to build.

That vision is under strain with Greek debt, the rise of the far right, an unparalleled refugee crisis and a revanchist Russia all contributing to a fracturing of European unity during the past two years.

British Prime Minister David Cameron said he's negotiated a deal to give Britain "special status in the EU" and will recommend it to his cabinet. (Reuters)

But a British vote to leave the European Union — making the country the first to withdraw from a union that has only expanded — could prove the most grievous wound of all.

And with polls showing a neck-and-neck contest, Germany has begun to quietly reckon with the unpalatable choice it would face if the British opt for out: It could watch the union that it has so carefully crafted begin to break apart. Or it could step into the kind of hegemonic European role that, ever since its calamitous drive for power in World War II, Berlin has assiduously avoided.

“Germany doesn’t want to be in this position,” said Daniela Schwarzer, director of the Berlin office of the German Marshall Fund. “It wants to lead in Europe. But it doesn’t want to do so alone.”

Along with France, Germany and Britain have long been the most essential players in Europe’s efforts to forge continental unity. But although the Germans have traditionally operated as the project’s accelerator, believing that a functioning union is the only long-term path to European peace and prosperity, Britain has long served as the brake, resisting attempts to fully integrate the continent politically and economically.

The sharply different approaches can be seen in the flags that fly from the parliament buildings in Berlin and London: Atop Germany’s Reichstag, the European Union’s circle of gold stars flaps side by side with the black, red and gold of the German national flag. At London’s Palace of Westminster, the Union Jack flutters alone.

Still, Britain’s presence in the 28-member European Union has mattered — and its absence would be keenly felt.

With France stuck in a deep economic and political malaise, the United Kingdom represents the European Union’s only other major power aside from Germany. It possesses Europe’s second-largest economy, its foremost financial center, a seat on the U.N. Security Council, an arsenal of nuclear weapons and the traditional bridge across the Atlantic to Washington.

If Britain opts for an exit — popularly known as “Brexit” — it could embolden anti-E.U. forces in other countries. The Czech prime minister has already warned of a “Czexit,” and populist parties across the continent have said they will push for their own referenda.

Concern about the possible fallout from a British decision to leave the European Union is not limited to Europe. The International Monetary Fund warned Tuesday that a British departure “could do severe regional and global damage by disrupting established trading relationships.”

Schwarzer said that the day after a vote for Brexit, if it happens, German Chancellor Angela Merkel will be under pressure to forcefully intervene to keep the European Union from spinning apart.

“Who else would do it in that moment?” Schwarzer asked.

Less than a year ago, the idea that Britain might strike out on its own seemed far-fetched. But the referendum promised by Prime Minister David Cameron has been more hotly contested than almost anyone anticipated.

Polls show a virtual tie. Most analysts give “in” a slight edge but acknowledge that the chances of an “out” vote are rising.

The Germans, of course, have no say in Britain’s choice. And they have been reluctant to weigh in too aggressively. Merkel has said she thinks it’s in Germany’s interest “for Great Britain to remain an active member in a strong and successful European Union” — a line similar to the one President Obama has used and is likely to use again when he visits the United Kingdom next week.

But Merkel has generally been low-key on Brexit, perhaps recognizing that she has political liabilities in Britain. She’s closely associated with the continent’s formerly open door to refugees at a time when Brexit campaigners are using the migrant issue to argue that Britain should get as far from Europe as it can.

Schäuble has been more outspoken. On a visit to London last month, he not only promised to shed tears if Britain leaves, he also told the BBC that it would be “a poison to the economy in the U.K., the European continent and for the global economy as well.”

Almut Möller, head of the Berlin office of the European Council on Foreign Relations, said such comments reflect just how deeply German policymakers fear the impact of Brexit on the European Union — an institution that has become inseparable from German identity.

“E.U. membership gave Germany liberation from its past and permission to reenter the family of Western states,” she said. “To lose Britain now would signal to the rest of the world — including to Russia and China — that the E.U. is dismantling.”

For a long time, such an unraveling was unthinkable, she said. But now it’s a real threat, regardless of which way Britain votes.

“These things have been taken for granted for many decades,” Möller said. “It’s a new environment now.”