The time has come to discuss new approaches to dealing with the problems of drugs in the Americas. After four decades of a hard-fought "war on drugs" the situation remains – in spite of progress in some areas – terribly and frustratingly stuck, with continued high levels of addiction, incarceration, and violence. When I and my fellow presidents and prime ministers met in April 2012 at the Summit of the Americas in Cartagena, Colombia, this frustration motivated us to mandate the Organisation of American States (OAS) to "explore new approaches" for addressing these problems.

The secretary general of the OAS, José Miguel Insulza, has now delivered his report. This document, the product of a rigorous and creative process by a team of prominent individuals from across the hemisphere's security, justice, health, education, government, business, and civil society sectors, provides a refreshingly broad and open set of perspectives on a debate that has become narrowed and polarised between drug "warriors" and "legalisers".

The report breaks new ground in suggesting that there are four different ways that the drug problem might be understood and dealt with over the next decade. Employing the transformative scenario planning methodology of Adam Kahane of Reos Partners and the University of Oxford, the report presents scenarios of what could happen: not predictions of what will happen and not recommendations of what should happen. As such these scenarios offer a new set of lenses with which to review drug problems and policies.

The first scenario is called "together". It envisages the drug problem as part of a larger insecurity problem, with weak state institutions unable to control organised crime and the violence and corruption it generates. The attempted response is to strengthen the capacity of judicial and public safety institutions to ensure security, through greater professionalisation, better partnering with citizens, new success indicators, and improved international cooperation.

This response offers opportunities for better citizen security, increased credibility of state institutions supported by increased public confidence and taxation, and renewed hemispheric partnership. But implementing it also poses challenges: to rebuild state institutions in the face of opposition from entrenched interests; weak, patchy, and lagging international co-operation; and the "balloon effect" of criminal activities shifting to places with weaker institutions.

The second scenario we call "pathways". In this case, the drug problem is seen to result from the current regime for controlling drugs through criminal sanctions (especially arrests and incarceration of users and low-level dealers), an approach that is producing too much harm. The attempted response is to try out, and learn from, alternative legal and regulatory regimes, starting with cannabis.

This response offers opportunities to develop better drug policies through experimentation; to reallocate resources from controlling drugs and drug users to preventing and treating problematic use, and to shrink some criminal markets and profits through regulation. The challenges in implementing this response are to manage the risks of experimentation, especially in transitioning from dealing with drugs through the criminal justice system to allowing drugs to be sold in regulated markets (possibly leading to increases in problematic use); and to deal with contraband and new inter-governmental tensions that result from differences in regimes between jurisdictions.

The third scenario is "resilience". In this scenario, the drug problem is seen to be a manifestation and magnifier of underlying social and economic dysfunctions that lead to violence and addiction. The response that is attempted is to strengthen communities and to improve public safety, health, education, and employment through bottom-up programmes created by local governments, businesses, and non-governmental organisations.

This response offers opportunities to create more inclusive, less violent, and healthier communities, which take an active role in fighting crime and drugs. The challenges in implementing this response are insufficient resources and capacities of many local governmental and non-governmental organisations to address these problems; and the lag time before this response reduces drug-related crime.

The fourth scenario is "disruption". Here the drug problem is seen to be that countries where drugs (especially cocaine) are produced and through which they transit are suffering unbearable and unfair costs. The response that is attempted by some governments is to abandon the fight against (or to reach an accommodation with) drug production within, and transit through, their territories.

This response offers the opportunity to reduce violence; to increase attention to domestic rather than international priorities; and to free up resources being spent on security and law enforcement. The challenges in implementing this response are reduced enforcement allowing the expansion of drug markets and profits; the possible capture of states by criminal organisations; and conflicts over violations of international treaties. This scenario warns of a dangerous sequence of events that could unfold if governments in the hemisphere fail to step up the effectiveness of their approach to dealing with drug problems – in other words, if they fail to seize the opportunities and meet the challenges raised by the first three scenarios.

Today in Antigua, Guatemala, the foreign ministers of all of the member countries of the OAS are holding their annual meeting, which this year will focus on the problems of drugs. The four scenarios offer this meeting a rich new language for understanding these problems and for discussing how they can more effectively be addressed. Any of these scenarios – or a combination of them, or possibly others – could occur. The decisions taken by leaders both in the Americas and the rest of the world will determine which scenario will occur.