If it weren't the site of a historical anachronism, hardly anyone would take any notice of Büchel, a small town west of Frankfurt, between Koblenz and Trier. Büchel is home to the last remaining atomic bombs in Germany, which have been stored here since the end of the Cold War. The air force base here allegedly houses around 20 B61 bombs, although the exact number is secret. But one thing is certain: each of them is many times more destructive than the bombs that wiped out Hiroshima and Nagasaki.

The atomic bombs in Büchel belong to the US, but in an emergency they would be flown to a target and dropped by German Tornado fighter-bombers. Pilots from the Tactical Air Force Wing 33 have been regularly practicing with dummy bombs for decades. The squadron is the main employer in the area, but the existence of these nuclear weapons doesn't show up anywhere on Büchel's website.

This strategy, in which other NATO states also participate, is called "nuclear sharing." Belgium, the Netherlands, Italy and Turkey also have US nuclear weapons on their territory. The concept of nuclear deterrence which underlies this strategy is still in great demand. As recently as 2012, it was confirmed by NATO as a "core element of collective defense."

Original goal: Nuclear disarmament

The mood was very different 50 years ago. In the UN's Nuclear Non-Proliferation Treaty, signed by the US, Great Britain and the Soviet Union on July 1, 1968, the signatory states undertook to prevent the proliferation of nuclear weapons. They were also striving for complete nuclear disarmament. Germany joined the treaty in 1975, and it has since been signed by more than 190 states.

For a long time, the treaty was regarded as the cornerstone of global disarmament efforts. Today, it appears to be little more than a toothless tiger. The Stockholm International Peace Research Institute (SIPRI) estimates there are still nearly 15,000 nuclear weapons worldwide. According to their research, the majority are held by the US (6,800) and Russia (7,000).

According to theologian Eberhard Schockenhoff, a professor at the Albert Ludwigs University of Freiburg and long-standing member of the German Ethics Council, the nuclear strategies of both sides are based on maintaining this residual stock, at least at its current level.

"This is ethically unacceptable," he said. The nuclear powers have "written off" the goal of nuclear disarmament — if not in public, at least behind closed doors.

Read more: US nukes in Germany: Top court rules against peace activist

The clock is ticking…

Tom Sauer, a political scientist and disarmament expert at the University of Antwerp, believes the treaty is "in total crisis." The last review conference in 2015 broke down, and he fears this will also be the case for the next one in 2020.

He believes that this state of affairs will continue until the signatory countries finally fulfil their obligations, which include a massive reduction of warheads down to zero, he says. "They promised that in 1968, but they're not doing it."

But instead of reducing their stockpiles, nuclear weapon states have been modernizing their weapons and incorporating new technology, such as sophisticated guidance systems. Experts say the danger of nuclear war is greater today than it has been for decades.

In January, a panel of scientists, including 17 Nobel Prize winners, set the symbolic Doomsday Clock — which measures how close the planet could be to catastrophe — at 11:58 p.m.. The readjustment put the clock at the closest it's been to midnight since the height of the Cold War.

'Symbolic reasons' for weapons

Back in Büchel, the peace movement is protesting against the nuclear weapons with the slogan "20 Weeks Against 20 Nukes." According to Karl-Heinz Kamp, head of the Berlin-based Federal Academy for Security Policy, the Büchel bombs — also set to be modernized — are still in Germany "primarily for symbolic reasons."

NATO members in Eastern Europe, in particular, attach great importance to "the symbol of America's nuclear pledge." After the fall of the Iron Curtain, NATO promised Russia that it would not deploy nuclear weapons on the territory of its new Eastern European member states. As a result, the weapons have remained in Central and Southern Europe.

But who are these nuclear weapons meant to intimidate? Those Bundeswehr Tornado jets, which could be called upon to transport the bombs to hit enemy targets, would probably only make it as far as Ukraine before running out of fuel.

And yet, despite upholding the goal of a world free of nuclear weapons in its coalition agreement earlier this year, the German government continues to tolerate the existence of these bombs on German soil. According to the governing coalition parties, the conservative Christian Democrats/Christian Social Union and the center-left Social Democrats, Germany has "an interest in participating in the strategic discussions and planning processes" of NATO.

Read more: Pakistan's indirect role in North Korea's nuclear program

'Nuclear genie is out of the bottle'

Among NATO members, only France and the United Kingdom, apart from the US, possess their own nuclear weapons. Russia, China, India, Pakistan, Israel and North Korea are the other nuclear powers in the world.

None of these nine states intend to abandon their nuclear weapons any time soon; they consider the bombs indispensable to their own security interests. For that reason, Kamp believes a world without nuclear weapons, which former US President Barack Obama backed to great applause in 2009, is not a realistic goal.

"The nuclear genie is out of the bottle," Kamp said, pointing out that materials and know-how are already available to those looking for them. Even in the unlikely event of complete disarmament, the weapons could still be reactivated at any time — not only by governments but, theoretically, also by large, wealthy corporations, which could also acquire the necessary expertise and fissile material.

New UN attempt

Has the danger posed by the continued existence of nuclear weapons been misjudged, 50 years after the signing of the non-proliferation treaty? Sauer fears this might be the case. He remains concerned that disarmament talks between the US and Russia are currently on hold, and that other countries, in particular Iran and Saudi Arabia, may be striving for nuclear weapons of their own.

Sauer hopes the United Nations will eventually support a complete ban on nuclear weapons, as outlined in a treaty adopted in July 2017 by 122 votes from its 193 member states. Once 50 countries ratify this treaty, it will become legally binding. To date, only 10 countries have done so — none of them major world powers.

If and when that happens, all the signatory countries would then consider nuclear weapons illegal, said Sauer. "The wind is changing, and nuclear powers are on the defensive."

Every evening at 1830 UTC, DW editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here.