Forty years ago, the multi-billion dollar international trade in endangered wildlife was largely a free-for-all. While many countries had imposed export restrictions to try and protect threatened species, there was no global trade agreement in place to provide a standard for such trade. So illegally exported products – like rhino horns or leopard skins – could still be legally imported into most countries, writes Theressa Frantz, Head of WWF South Africa’s Environmental Programmes Unit.

This made a mockery of national efforts to save endangered species, while also undermining hopes that countries could sustainably boost their legal wildlife trade for the benefit of species and people. The answer – or at least the agreed approach – was the launch in 1975 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

One of its earliest decisions was to ban all international trade in rhino horn since demand was rapidly driving some rhino species towards extinction, with black rhino numbers in particular plunging across Africa. The ban supported African countries, especially South Africa, which were battling to increase their rhino populations.

But here we are four decades later with rhinos being poached in alarming numbers in southern and east Africa again. And with a raft of rhino issues up for debate at the 17th CITES Conference of the Parties (CoP) – critics are questioning whether the Convention has the teeth to make a difference.

CITES can certainly point to an enormous body of work, with over 35 000 species of animals and plants now under some form of international trade regulation. Some successes are evident from well-regulated legal trade (such as crocodiles and vicuna) and from global trade bans (elephants saw a steep decrease in poaching after the international ban in 1989 until a new wave of illegal killing began in 2007).

But the pressure keeps growing as the world’s population rises and consumer demand for wildlife and wildlife products – for food, medicine, furniture, status – soars with it.

In response, CITES has grown bigger and more ambitious. Fittingly kicking off on Heritage Day –  24 September – CoP17 in South Africa will be the largest ever with a record 183 Parties and an unprecedented number of trade proposals and agenda items.

For two weeks, conservation leaders from around the world will gather in Johannesburg to debate changes to the levels of protection afforded to over 60 categories of animals and plants as well as other critical issues from tackling corruption to reducing demand and combating wildlife crimes, as well as how to make the Convention more effective.

With international organised crime networks driving a global surge in illegal widlife trade and the legal sustainable use of threatened wildlife increasingly in the firing line in many countries, we can expect to hear a lot of criticism of the Convention leading up to and during this meeting.

Some animal rights activists will say that its measures do not go far enough, and that allowing any consumptive use of charismatic animals like elephants and lions is repugnant. On the other side of the debate, supporters of sustainable use will argue that the Convention has become subservient to a Western animal rights agenda and that it has effectively become neo-colonial.

The reality is that the Convention recognises that people and states are the best protectors of their own wildlife, but that international co-operation is essential for the conservation of certain species due to over-exploitation through international trade.

Furthermore, CITES is about far more than just whether or not to ban trade in endangered species.

The Convention can compel countries to take specific measure to tackle illegal trade – actions that reinforce existing bans. If countries do not comply they face the threat of trade sanctions under CITES. Nineteen Asian and African countries implicated in the illegal ivory trade are currently part of the National Ivory Action Plan process, which was kickstarted at the previous CoP and is beginning to show results.

Meanwhile, Viet Nam and Mozambique have to report on their efforts to crack down on the illegal rhino horn trade. With little progress to point to, Viet Nam will be under severe scrutiny – as will CITES itself, given the global surge in illegal wildlife trade and all the politics involved.

CITES is a consensus-orientated body but it can take decisions by two-thirds majority when required, so that some debates have inevitably become politicised.

On two recent occasions the Convention came close to banning international trade in polar bear, despite the fact that trade is not a threat, especially compared to the impact of climate change. On the other hand, for many years fisheries interests delayed the implementation of necessary measures to regulate trade in some shark species.

Debates on elephants and ivory have often proved a particularly bitter issue and this year’s CoP will be no different, especially as the Great Elephant Census has just detailed an alarming decrease in the overall population of Africa’s savanna elephants since 2007, primarily due to poaching and illegal trade.

Other issues – including rhinos and sharks – are also likely to test CITES’ prized consensus as countries and conservationists argue passionately for what they believe will best safeguard threatened wildlife and support the sustainable development of local communities.

There will no doubt be opportunities for guarded optimism. While most debates will focus on additional protection – for species as diverse as pangolins, thresher sharks, rosewood trees and the pyschedelic rock gecko – governments will also vote on whether to reduce trade restrictions on species that have recovered.

Seeing the Convention agree that the trade rules on the peregrine falcon or the mountain zebra can be relaxed in the light of the improved status of these species shows that CITES can work.

So like all international treaties, CITES has had its fair share of successes and failures. But the fact that it is attracting criticism from diametrically opposed camps is the best evidence that it is doing something right.

It will be a tough two weeks. But if bold, ambitious measures can be agreed – such as the threat of sanctions on Viet Nam if it does not agree to concrete, timebound actions on the rhino horn trade or rigorous, independent monitoring of the national ivory action plan process – this CoP will be viewed in future as one of the most important moments in the fight to conserve the world’s endangered wildlife.

A version of this article appeared in the South African Sunday Times, 18 September 2016.