On April 5 2009, when US President Barack Obama spoke in Prague's historic Hradcany Square, he was addressing a crowd of Czechs but his audience was global. There was palpable excitement as the young new president outlined a vision of a world freed, at last, of the threat of nuclear weapons.
Hopes were raised of really serious movement towards nuclear disarmament, which in turn would drive a reinvigorated commitment to nuclear non-proliferation and nuclear security.
There were additional grounds for optimism over the following months. Russia and the US resumed negotiations on cutting their nuclear stockpiles; the International Commission on Nuclear Non-Proliferation and Disarmament - co-sponsored by the Australian and Japanese governments - outlined a comprehensive but sharply practical agenda for further progress on the full nuclear weapons menu in 2009; Washington hosted a successful nuclear security summit in April 2010 (followed by a second one in Seoul two years later); and in May 2010, the Nuclear Non-Proliferation Treaty Review Conference also came to some critical agreements that had completely eluded its failed predecessor five years earlier.
Alas, by the end of 2012, much of this sense of optimism had evaporated, and the Nuclear Weapons: The State of Play report helps to explain why.
The first in a proposed series, the report assesses the progress made by the end of 2012 on the more than 200 commitments and recommendations of the 2010 NPT review conference, the 2010 and 2012 nuclear security summits, and the 2009 ICNND report.
The state-of-play report documents pockets of progress in each of the four categories it addresses chapter by chapter (nuclear disarmament, nuclear non-proliferation, nuclear security, and the security risks associated with peaceful uses of nuclear energy). However, this is not occurring on the scale and at the speed necessary to walk us back to safety from the nuclear precipice on which the world is presently poised rather precariously.
The weakest of the four areas has been nuclear disarmament. Almost 18,000 nuclear weapons remain in the arsenals of the nine nuclear-armed states, with a combined destructive capacity of about 120,000 Hiroshima-sized bombs.
About 94 per cent of the weapons are in Russian and US arsenals, while at the other end, North Korea may have up to 10 nuclear weapons and the rest (China, France, India, Israel, Pakistan and Britain) between 80 and 300 each.
This is why the primary responsibility for leading the world away from the nuclear cliff rests with Moscow and Washington.
In addition, efforts are under way or planned in all of these nations to upgrade and modernise their nuclear stockpiles and deployment strategies, with little enthusiasm evident for modifying the doctrines underpinning their use, or reducing their often dangerously high-alert status.
Some 2000 nuclear weapons are maintained at a level of readiness enabling them to be launched within minutes, maximising the chances of human error or system malfunction.
New START left both US and Russian stockpiles intact, their high-alert status undisturbed, weapons-modernisation programs in place, disagreements about missile defence and conventional-arms imbalances unresolved - and talks on further draw-downs going nowhere.
Nuclear weapons numbers have decreased overall as a result of US and Russian actions in particular, but there has been an acceleration of nuclear-weapons programs in India, Pakistan and China.
The unavoidable conclusion, therefore, is that while nuclear disarmament continues to be very strongly supported by the overwhelming majority of the world's countries (and, going by public opinion polls, the clear majority of the world's people), it remains for every nuclear-armed state at best an open-ended, incremental process, conditional on peace, stability and good order first being established in every volatile region.
There is no appetite among them for a multilateral disarmament process and no disposition to discuss disarmament timelines.
In sum, on the evidence of the size of their weapons arsenals, fissile material stocks, force modernisation plans, stated doctrine and known deployment practices, all nine nuclear-armed states foresee indefinite retention of nuclear weapons and a continuing role for them in their national security policies.
The NPT's five recognised nuclear-weapon states (China, France, Russia, Britain, and the US) place greater emphasis and a higher value on the prevention of nuclear proliferation than they do on nuclear disarmament. Unfortunately, this is putting the nuclear non-proliferation regime under increasing strain, and reinforcing resistance to predominantly Western efforts to enforce new safeguard measures.
While the NPT's record of containing proliferation has been very good thus far, UN secretary-general Kofi Annan's High-level Panel on Threats, Challenges and Change rightly warned in December 2004: ''We are approaching a point at which the erosion of the non-proliferation regime could become irreversible and result in a cascade of proliferation.''
The situation has further deteriorated in the years since then. A succession of new studies confirm the catastrophic humanitarian and environmental consequences of even a limited regional nuclear war.
Current UN Secretary-General Ban Ki-moon's welcome calls to prioritise nuclear arms control and disarmament have so far fallen largely on deaf ears.
Civil society organisations, however dedicated and active, have achieved little of the traction needed to put relevant governments under serious political pressure.
There has been insignificant progress on calls for additional nuclear-weapon-free zones to deepen and consolidate the NPT or on the nuclear powers ratifying protocols to the existing regimes.
The Middle East nuclear-weapon-free zone conference mandated by the NPT review conference for 2012 has been postponed indefinitely.
The voluntary moratorium on nuclear testing is continued by most but not by North Korea, and the Comprehensive Test Ban Treaty is unlikely to enter into force any time soon.
There has been no progress in beginning negotiations on a global ban on the production of fissile material for nuclear-weapon purposes, a central non-proliferation policy objective.
All this helps to explain why the nuclear arms control and disarmament agenda is still stuck firmly in the zone of vulnerability. Yet authoritative roadmaps have been provided by the NPT review conference, the nuclear security summits and by the ICNND to walk us back to zones of safety and comfort.
The goal of Nuclear Weapons: The State of Play is not to criticise and castigate but to advance helpfully the global nuclear policy debate by encouraging the relevant states to be guided by those roadmaps.
Ramesh Thakur, professor in the ANU Crawford School of Public Policy, is director of the Centre for Nuclear Non-Proliferation and Disarmament.
Nuclear Weapons: The State of Play may be downloaded from cnnd.anu.edu.au