The terrorist bombs in London caused immense suffering and grief. This crime rightly received nearly universal condemnation. Violence does not solve any problems, it only aggravates them.

Yet this tragedy only foreshadows much worse future catastrophes if the world continues on its current course.

As long as the big powers insist on maintaining nuclear weapons, claiming they need them to protect their security, they cannot expect to prevent other countries and terrorist organizations from acquiring such weapons–and using them.

The atomic bomb dropped on Hiroshima killed over 200,000 people. Today’s nuclear bombs are vastly more powerful. If even one nuclear device had been detonated in a parked car or a sailboat on the Thames, the Center of London would be strewn with smoking, radioactive rubble and over a million people might have been killed outright, and scores more would die slowly from radiation disease.

The double standard, “Nuclear weapons are good for us, but bad for you”, is stupid and unconvincing. Believing that nuclear weapons technology can be kept secret forever is naive.

Those who still believe in the fairy-tale of “deterrence theory” better wake up to the age of suicide bombers. Anyone convinced to go straight to heaven if blown up cannot be “deterred” by the threat of horrendous retaliation.

Governments that order tons of bombs to be rained on Iraq and Afghanistan should not be surprised if they plant ideas in the minds of eager imitators. Osama bin Laden once benefitted from support and training financed by the CIA.

Richard Falk, long a Professor of International Law at Princeton University, rightly pointed out: “The greatest utopians are those who call themselves ‘realists,’ because they falsely believe that we can survive the nuclear age with politics as usual.

The true realists are those who recognize the need for change.”

What changes must we make if we want humanity to survive?

[1] We must stop believing that problems can be solved by applying offensive military force. That only encourages others to pay back in kind. Policing to stop criminals and defense against a foreign attack are justified, but not military interventions abroad.

[2] Thirty-seven years after signing the Nuclear Non-Proliferation Treaty, it is time for the nuclear powers to fulfill their commitment to nuclear disarmament.

We also need a vastly more open world, where all nuclear weapons are verifiably destroyed, and the manufacturing of new ones cannot be hidden. The International Atomic Energy Agency (IAEA) can now inspect only sites that member countries voluntarily place under its supervision. If a suspected weapons smuggler could tell a border guard, “You may check under my seat, but don’t open the trunk,” such an “inspection” would be meaningless. The IAEA must have the power to inspect any suspected nuclear facilities, anywhere in the world, without advance warning, otherwise it is impossible to prevent the spread of nuclear weapons.

The governments that now possess nuclear weapons object to such intrusive inspections as a “violation of their sovereignty.” Yet many airline passengers also protested at first against having their luggage searched for guns or explosives, when such searches were introduced after a series of fatal hijackings. Today, passengers realize that such inspections protect their own security. Those who have nothing to hide have nothing to fear. Sooner or later, governments will reach the same conclusion. The question is only whether this will happen before or after the first terrorist nuclear bomb explodes.

[3] We need to address the root causes of terrorism: long festering unresolved conflicts. Peaceful conflict transformation is a skill that can be taught and learned. Johan Galtung, widely regarded as founder of the field of peace research, was able to help end a longstanding border conflict between Ecuador and Peru over which they had fought four wars by suggesting to make the disputed territory into a “binational zone with a natural park”, jointly administered. This peaceful intervention cost nearly nothing compared with a military peacekeeping operation.

We need a UN Organization for Mediation, with several hundred trained mediators who can help prevent conflicts from erupting into violence. This is a very inexpensive, worthwhile investment in human survival, compared with the trillion dollars the world spends each year to arm millions of troops, which only make the world collectively less secure.

If we cling to obsolete ways of thinking–that threatening others will make us safe–we face extinction as a human species, like other species that failed to adapt to new conditions.

Is it a realistic prospect to get rid of all nuclear weapons? Certainly more realistic than waiting until they are used. Some have argued that we cannot disinvent nuclear weapons and therefore will have to live with them as long as civilization exists. But nobody has disinvented cannibalism either, we have simply learned to abhor it. Can’t we learn to abhor equally the incineration of entire cities with nuclear weapons?

Dietrich Fischer is Academic Director of the European University Center for Peace Studies in Stadtschlaining, Austria, and a member of TRANSCEND, a peace and development network.