The issue is so secret that it isn't even listed on any daily agenda at NATO headquarters. When military officials and diplomats speak about it in Brussels, they meet privately and in very small groups -- sometimes only with two or three people at a time. There is a reason why signs are displayed in the headquarters reading, "no classified conversation."
And this issue is extremely sensitive. The alliance wants to avoid a public discussion at any cost. Such a debate, one diplomat warns, could trigger an "avalanche." The foundations of the trans-Atlantic security architecture would be endangered if this "Pandora's box" were to be opened.
The discussion surrounds nuclear deterrent. For decades, the final line of defense for Europe against possible Russian aggression has been provided by the American nuclear arsenal. But since Donald Trump's election as the 45th president of the United States, officials in Berlin and Brussels are no longer certain that Washington will continue to hold a protective hand over Europe.
It isn't yet clear what foreign policy course the new administration will take -- that is, if it takes one at all. It could be that Trump will run US foreign policy under the same principle with which he operates his corporate empire: a maximum level of unpredictability.
With his disparaging statements during the campaign about NATO being "obsolete," Trump has already created doubts about the Americans' loyalty to the alliance. Consequently, Europe has begun preparing for a future in which it is likely to have to pick up a much greater share of the costs for its security.
But what happens if the president-elect has an even more fundamental shift in mind for American security policy? What if he questions the nuclear shield that provided security to Europe during the Cold War?
For more than 60 years, Germany entrusted its security to NATO and its leading power, the United States. Without a credible deterrent, the European NATO member states would be vulnerable to possible threats from Russia. It would be the end of the trans-Atlantic alliance.
Could the French or British Step In?
In European capitals, officials have been contemplating the possibility of a European nuclear deterrent since Trump's election. The hurdles -- military, political and international law -- are massive and there are no concrete intentions or plans. Still, French diplomats in Brussels have already been discussing the issue with their counterparts from other member states: Could the French and the British, who both possess nuclear arsenals, step in to provide protection for other countries like Germany?
The article you are reading originally appeared in German in issue 50/2016 (December 10, 2016) of DER SPIEGEL.
"It's good that this is finally being discussed," says Jan Techau, director of the Holbrooke Forum at the American Academy in Berlin. "The question of Europe's future nuclear defense is the elephant in the room in the European security debate. If the United States' nuclear security guarantee disappears, then it will be important to clarify who will protect us in the future. And how do we prevent ourselves from becoming blackmailable over the nuclear issue in the future?"
An essay in the November issue of Foreign Affairs argues that if Trump seriously questions the American guarantees, Berlin will have to consider establishing a European nuclear deterrent on the basis of the French and British capabilities. Germany's respected Frankfurter Allgemeine Zeitung newspaper, meanwhile, even contemplated the "unthinkable" in an editorial: a German bomb.
'The Last Thing Germany Needs Now'
Politicians in Berlin want to prevent a debate at all costs. "A public debate over what happens if Trump were to change the American nuclear doctrine is the very last thing that Germany needs right now," says Wolfgang Ischinger, head of the Munich Security Conference. "It would be a catastrophic mistake if Berlin of all places were to start that kind of discussion. Might Germany perhaps actually want a nuclear weapon, despite all promises to the contrary? That would provide fodder for any anti-German campaign."
The debate however, is no longer relegated the relatively safe circles of think tanks and foreign policy publications. In an interview that gained attention internationally in mid-November, Roderich Kiesewetter, the chairman for the conservative Christian Democrats on the Foreign Policy Committee in German parliament proposed a French-British nuclear shield in the event Trump calls into question American protection for Europe. "The US nuclear shield and nuclear security guarantees are imperative for Europe," he told Reuters. "If the United States no longer wants to provide this guarantee, Europe still needs nuclear protection for deterrent purposes."
Last weekend, Angela Merkel's chief of staff, Peter Altmaier, said in an interview that providing a nuclear shield for Europe was in America's "security policy interest." Besides, he said, "two EU member states possess nuclear weapons."
Unpopular and Politically Explosive
Kiesewetter argues that Europe must prepare for all eventualities. "There can be no limits placed on our security debate," he says. The CDU security policy expert is a former colonel in the German armed forces and also did stints at both NATO headquarters in Brussels and at the alliance's military headquarters in Mons, Belgium. After Trump's election, he spoke not only to French and British diplomats, but also explored views within the German government.
He says he spoke with Christoph Heusgen, Merkel's security adviser, and with Defense Ministry Policy Director Gésa von Geyr. Kiesewetter says the issue is not one that either the Chancellery or the Defense Ministry is taking up. At the same time, he says, he also didn't get the impression that his ideas had been dismissed as fantasy either.
It's understandable that the German government wants to quickly end the debate. The issue is politically explosive and would also be highly unpopular. In polls, more than 90 percent of Germans have opposed the idea of Germany possessing its own nuclear bomb. The American nuclear shield has so far offered Germans the luxury of standing on the right side of the moral debate even as Washington guarantees their security.
'The Wrong Message'
Officials in Brussels also aren't thrilled by the statements coming out of Berlin. "The fact that these considerations have been made public is deeply concerning," a diplomat representing one NATO member state says. "It would send the wrong message to America but also the grotesquely wrong message to Russia," says Ischinger. He warns that the message cannot be sent to Washington that Europe is in the process of exploring alternatives to the American protective shield.
But military officers and diplomats are addressing the issue inside NATO headquarters. One diplomat says that these ideas have been circulating "informally and off-the-record" inside NATO headquarters for a few months now. "The statements made by Mr. Kiesewetter reflect the concerns that exist everywhere in Europe over what Trump's inauguration will mean for US engagement and its strategy on nuclear deterrent."
On the nuclear question, Trump has attracted attention primarily for off-the-cuff remarks he made during the campaign. "If we have nuclear weapons, why can't we use them?" he allegedly said during a foreign policy briefing in the summer.
During the campaign, he also toyed with the idea of eliminating the US nuclear shield that provides protection to Japan and South Korea. Essentially, he bluntly suggested that the two Asian nations ought to develop their own nuclear weapons. Europeans have worried ever since that a similar threat could be directed at them.
Such comments come at a time when Moscow is more focused on its role as a nuclear power than it ever has been since the end of the Cold War. Like the United States, Russia is currently in the process of modernizing its nuclear arsenal. For a few years now, veiled threats about Moscow's nuclear arsenal have become part of the standard repertoire in President Vladimir Putin's rhetoric.
The British and French Deterrents
Europe would face very high hurdles if it sought to create its own nuclear shield. Why would Britain, currently in the process of leaving the European Union, even agree to it? And why would the French give the Germans any say when it comes to their Force de Frappe deterrent? Both have allegedly declined to consider the notion in initial probes in Brussels. But there's yet a bigger issue. Even if they were to cooperate, would the nuclear arsenal held by European nuclear powers even be sufficient to guarantee a nuclear deterrent?
Likely, yes. Taken together, Britain and France may only have 10 percent as many nuclear weapons as the Americans, but their second-strike capability is strong enough to effectively deter potential attackers.
The nuclear shield the United States has created for NATO member states is comprised of two components: The strategic element consists of hundreds of intercontinental ballistic missiles, a massive bomber fleet and around a dozen Ohio-class submarines. Each submarine has over 20 Trident II (D5) missiles with multiple warheads at its disposal.
The tactical element specially designed for a European theater of war is comprised of a little more than 180 B61-3 and -4 aircraft-carried missiles that are stationed at six air bases in five different NATO member states. Up to 20 nuclear bombs are stored in the village of Büchel, Germany, deployable on German Tornado fighter jets.
Together, France and Britain have around 450 nuclear warheads. France uses four strategic ballistic missile submarines, with each capable of carrying 16 missiles with four to six multiple warheads. The country also has around 50 nuclear strike-capable Mirage 2000N and Rafale fighter jets that are each equipped with nuclear-armed cruise missiles.
Britain has four strategic Vanguard-class missile submarines that also hold Trident II (D5) missiles that can carry up to 160 nuclear warheads. Technologically, however, the British are dependent on the Americans.
'Sufficient for Defending Germany'
"Viewed entirely from a military perspective, the nuclear weapons held by France and Britain would likely be sufficient for defending Germany," says the American Academy's Techau. The fact that they don't have the same number of nuclear weapons as Russia doesn't really matter. "The second-strike capability, which is decisive for deterrence, exists."
Politically, though, things get more complicated. France has always viewed its nuclear capability as a national asset and has never placed its weapons under a NATO mandate. It coordinates with Brussels, but would decide independently of the alliance on any potential deployment of its nuclear weapons.
Even during the Cold War, several political efforts were made to establish German-French nuclear cooperation, but nothing ever came of them.
Chancellor Konrad Adenauer and Defense Minister Franz Josef Strauss had hoped to work together with Paris. But Charles de Gaulle immediately halted the secret project as soon as he was elected in 1958.
Later, two years after he got voted out of office, former German Chancellor Helmut Schmidt of the center-left Social Democrats (SPD) also proposed a deal. He suggested that France expand its nuclear deterrent to include Germany. In exchange, West Germany would offer its "capital and financial strength" in order to help finance the French nuclear weapons program.
France Shunned Germany
Helmut Kohl, who was chancellor at the time, dismissed the idea as an "intellectual gimmick." A secret protocol dating from December 1985 -- and only made public at the beginning of this year -- showed why Kohl's distrust had been justified. In it, French President François Mitterrand admits to Kohl that France would be unwilling to "provide Germany with nuclear protection." He said France's nuclear potential could only serve to protect "a small territory" -- in other words, France. If Paris were to extend its protection, the French leader said, it would expose his country to a "lethal threat." In other words, Mitterrand did not want to risk dying to defend Germany.
Even if France were to change its position, it would be tricky under international law for Germany to participate militarily in a European nuclear shield. Whether or not Germany's participation in NATO's nuclear shield is permitted under international law has already been the subject of considerable debate. An actual German bomb would violate the terms of both the Nuclear Non-Proliferation Treaty (NPT) and the Two Plus Four Agreement, the treaty which resulted in Germany's reunification.
By becoming a signatory to the NPT in 1975, the Germans committed "not to receive the transfer from any transferor of nuclear weapons or other nuclear explosive devices or of control over such weapons or explosive devices directly, or indirectly." During negotiations over German reunification in 1990, then-Chancellor Kohl also affirmed Germany's "renunciation" of the manufacture, possession and control of nuclear weapons. The provision became an integral part of the Two Plus Four Agreement.
A European Nuclear Power?
But the Germans always left a few loopholes open. In diplomatic notes attached to German NPT ratification documents, the government in Bonn stated at the time it had signed it "convinced that no stipulation in the treaty can be construed to hinder the further development European unification, especially the creation of a European Union with appropriate capabilities." Wolfgang Mischnick, parliamentary floor leader of the Free Democratic Party, which shared power with Kohl's Christian Democrats at the time of reunification, publicly clarified what that meant during a session of the Bundestag on February 20, 1974: "It is still possible to develop a European nuclear power," he said.
Forty years later the issue is actually now being raised for the first time. With it also comes the question of the degree to which Europeans actually trust each other. The real test will come if the United States decides to withdraw its nuclear support from Europe. Then Europeans would be forced to ask whether Paris and London were prepared to guarantee security for Germany and other Europeans. And also: Would Germans place their trust in a nuclear shield provided by their European partners?
For France, which always found Europe's reliance on NATO to be suspect, a European nuclear shield could also present an opportunity. A nuclear arsenal under French leadership, but large parts of which were financed by the Germans, would place the economically weakened country in a dominant position in terms of European security.