Five years ago hopes were high that the world was at last seriously headed toward nuclear disarmament. In April 2009 the then exciting new U.S. President Barack Obama gave a stirring and inspiring speech in Prague in which he outlined his dream of a world freed of the existence and threat of nuclear weapons.

The United States and Russia negotiated a new strategic arms reduction treaty (New START) that cuts their deployed strategic nuclear warheads by one-third to 1,550 each. The inaugural Nuclear Security Summit in Washington attracted broad international buy-in to an ambitious new agenda.

In contrast to the total and scandalous failure of its 2005 predecessor, the Eighth Non-Proliferation Treaty (NPT) Review Conference of May 2010 was a modest success.

In sum, there were grounds for optimism that there would be significant forward movement on the nuclear disarmament, nonproliferation and security agendas.

By the end of 2012, as reported in my Centre’s inaugural “Nuclear Weapons: The State of Play” report, much of this sense of optimism had evaporated. By the end of 2014, as our followup report “Nuclear Weapons: The State of Play 2015” documents, the fading optimism has given way to pessimism.

North Korea conducted its third nuclear test in early 2013 and the Comprehensive Nuclear Test Ban Treaty (CTBT) is yet to enter into force.

We are no closer to resolving the challenge posed by North Korea and a comprehensive agreement on Iran eluded negotiators by the extended deadline of Nov. 24, 2014. The push for talks on a nuclear-weapon-free zone in the Middle East called for by earlier NPT conferences has stalled and the region remains highly volatile.

New START was signed and ratified, but the treaty left stockpiles intact and disagreements about missile defense and conventional-arms imbalances unresolved. Nuclear weapons numbers have decreased overall but increased in Asia; nuclear-weapons programs in India, Pakistan and China have accelerated; and fissile material production to make still more warheads is not yet banned.

Cyber threats to nuclear weapons systems have intensified, outer space remains at risk of nuclearization, and the upsurge of geopolitical tensions over the crisis in Ukraine produced flawed conclusions about the folly of giving up nuclear weapons on the one hand, and open reminders about Russia’s substantial nuclear arsenal, on the other.

The peoples of the world recognize the dangers of nuclear arsenals. Curiously, however, their concerns and fears find little reflection in the media coverage or in governments’ policy priorities.

As part of the Global Attitudes survey conducted by the U.S. Pew Research Center from March 17 to June 5, 2014, a total of 48,643 respondents in 44 countries were asked which one of the following five poses the gravest threat to the world: nuclear weapons, inequality, religious-ethnic hatred, environmental pollution, or AIDS and other diseases?

Nuclear weapons was chosen as the top threat in 10 of the 44 countries polled (including two nuclear-armed states Russia and Pakistan), and as the second gravest threat in another 16 (including China).

The regional breakdown of the median responses shows that nuclear weapons were considered to be the top threat to the world by 20 percent of the people in the Middle East, 19 percent in Europe, 21 percent in Asia, 26 percent in Latin America, 22 percent in Africa, and 23 percent even in the U.S.

No Latin American country has nuclear weapons The continent’s anti-nuclear commitment was reinforced by the negotiation of the regional nuclear-weapon-free zone in 1967 under the Treaty of Tlatelolco, which consolidates and deepens the NPT prohibitions on getting the bomb.

Since then virtually the entire Southern Hemisphere has embraced additional comparable zones in the South Pacific, Southeast Asia and Africa.

Consequently looking out at the world from our vantage point, we see no security upsides by way of benefits from nuclear weapons; only risks.

Indeed it helps to conceptualize the nuclear weapons challenge in the language of risks. Originally many countries acquired the bomb in order to help manage national security risks.

As the four famous strategic heavyweights of Henry Kissinger, Sam Nunn, William Perry and George Shultz — all card-carrying realists — have argued in a series of five influential articles in The Wall Street Journal between 2007 and 2013, the risks of nuclear proliferation and terrorism posed by the existence of nuclear weapons far outweigh their modest contributions to security since the end of the Cold War.

Viewed through this lens, the nuclear risks agenda has four components:

• Risk management.•

We must ensure that existing weapons stockpiles are not used; that all nuclear weapons and materials are secured against theft and leakage to rogue actors like terrorist groups; and that all nuclear reactors and plants have fail-safe safety measures in place with respect to designs, controls, disposal and accident response systems.

• Risk reduction.•

This means strengthening the stability-enhancing features of deterrence, such as robust command and control systems and deployment on submarines. As part of this, it would help if Russia and the U.S. took their approximately 1,800 warheads off high-alert, ready to launch within minutes of threats being supposedly detected.

If other countries abandoned interest in things like tactical nuclear weapons that have to be deployed on the forward edges of potential battlefields and require some pre-delegation of authority to use to battlefield commanders. Because any use of nuclear weapons could be catastrophic for planet Earth, the decision must be restricted to the highest political and military authorities.

• Risk minimization• .

There is no national security objectives that Russia and the U.S. could not meet with a total arsenal of under 500 nuclear warheads each deployed in the air (a few), on land (some), and at sea (most). And if all the others froze their arsenals at current levels, this would give us a global stockpile of 2,000 bombs instead of the current total of nearly 16,400.

Ratifying and bringing into force the CTBT, concluding a new fissile material cutoff treaty, banning the nuclear weaponization of outer space, respecting one another’s sensitivities on missile defense programs and conventional military imbalances etc. would all contribute to minimizing risks of reversals and setbacks.

None of these steps would jeopardize the national security of any of the nuclear-armed states; each would enhance regional and international security modestly; all in combination would greatly strengthen global security.

• Risk elimination.•

Successive blue ribbon international commissions, from the Canberra Commission through the Tokyo Forum, Blix Commission, and Evans-Kawaguchi Commission, have emphatically reaffirmed three core propositions.

As long as any state has nuclear weapons, others will want them. As long as they exist, they will be used again someday, if not by design and intent, then through miscalculation, accident, rogue launch or system malfunction. Any such use anywhere could spell catastrophe for the planet.

The only guarantee of zero nuclear weapons risk, therefore, is to move to zero nuclear weapons possession by a carefully managed process.

Ramesh Thakur is director of the Center for Nuclear Non-Proliferation and Disarmament, The Australian National University. “Nuclear Weapons: The State of Play 2015,” written by Gareth Evans, Tanya Ogilvie-White, and Ramesh Thakur, can be downloaded for free from: cnnd.crawford.anu.edu.au/sites/default/files/publication/cnnd_crawford_anu_edu_au/2015-02/printer_copy.pdf