As the debate rages over whether Charles Taylor will languish in a British prison or elsewhere, much more important should be the discussion into how the former President of Liberia could have been prevented from aiding and abetting such atrocities in the first place.

As Arms Control Manager for Amnesty International, I have spent two decades researching and trying to expose the devastating impact of a blatantly irresponsible and, at times, unlawful trade in weapons - a trade which has fuelled some of the world's worst atrocities, including killings, rapes and mutilations as seen during the conflicts in Sierra Leone, Liberia and elsewhere.

What has always been obvious is that the world should not wait for arms to fuel a catastrophic human rights crisis before the great powers call time.

Security Council action has its benefits but it often comes late. It's time the world rejected the body bag approach to arms control.

During the summer of 2000, I presented evidence at a UN Security Council hearing into how the illicit diamonds revenue was converted into arms purchases.

This UN hearing was not only the first to try to understand a problem that perpetuates conflict, but also marked a watershed by providing evidence and official recognition of the inadequacy of existing arms trade standards and regulations.

During the UN hearing in 2000, several things were clear. Firstly, the deadly and dangerous weapons fuelling the conflict in Sierra Leone were traded and delivered not just at national or even regional level but a global one.

Secondly, the absence of any legally binding international standards governing arms exports meant that nothing was effectively done to stop the flow of arms into Sierra Leone - all we had was a UN arms embargo finally agreed a full six years later.

Thirdly, even once imposed, the UN embargo was circumvented on a massive scale not least because national systems to control the arms trade were so weak and poorly implemented.

Inadequate customs inspections and public record keeping as well as unverified trade documentation meant that arms from the post-Soviet Union stockpiles of east European countries like Slovakia and Ukraine easily found their way to Charles Taylor through the complicit states of Burkina Faso and the Ivory Coast.

The deals were set up by arms brokers from Israel, Kenya, the Netherlands, Russia, South Africa and Ukraine, yet jurisdictional loopholes meant none was tried at the time.

Inadequate registration and control of air and sea transporters meant that companies from Hong Kong, the United Arab Emirates and the United Kingdom were used to ship the arms. Meanwhile, payments made with the revenue from the illicit trade in Sierra Leone's diamonds were channelled through bank accounts as far afield as Singapore, Cyprus and the USA, without investigation.

As we now know, this litany of failures massively contributed to the horrors of Sierra Leone's civil war. Tens of thousands civilians were killed and many more mutilated and wounded, thousands of women were raped, more than 5,000 boys and girls were forcibly recruited as child soldiers and over one third of the population were forced to flee their homes.

Charles Taylor's sentencing sends an important message to high-ranking state officials; no matter who you are or what position you hold, you will be brought to justice for your crimes.

It should also act as powerful a reminder to governments to reject the "body bag" approach and to ensure through their actions that they will put an end to irresponsible arms transfers. In just over a month's time, UN member states will gather in New York to negotiate the text of the world's first ever Arms Trade Treaty.

This July's UN negotiating conference is an historic moment to establish a tough, comprehensive global Arms Trade Treaty with common rules to help protect human rights. The experience of Sierra Leone and Charles Taylor's Liberia makes it clear what is needed.

Instead of having to wait for Security Council agreement on a UN arms embargo, which is imposed after the catastrophe has already happened, the treaty must require that no arms transfers can ever be approved if there is a substantial risk that the arms would be used to commit or facilitate serious violations of human rights or fuel persistent unlawful armed violence - what we call the "Golden Rule".

To ensure respect for this "Golden Rule" and tackle the multifaceted nature of the arms trade, the treaty must also cover all types of conventional weapons, munitions, armaments and related equipment as well as all forms of trade and government-to-government transfers. It should require governments to strictly regulate arms brokering, transport and financial services for such transfers.

To have teeth, the Treaty must require governments to undertake rigorous risk assessments prior to any authorisation of an arms transfer or transaction, and publicly to report on all authorisations and deliveries. Trading without permission or illegally diverting arms should be a criminal offence and states that fail to comply with the treaty obligations should be held to account.

Of course, sceptics may view this as an unrealistic shopping list but past failures have shown that standards and regulations that are not sufficiently comprehensive are destined to fail. The case of Charles Taylor and Sierra Leone's civil war shows that the exclusion of a human rights "Golden Rule" would invalidate the whole preventative value of a treaty. Similarly, without thorough prior risk assessments, strict licensing, public reporting and criminalisation of illicit trafficking, those responsible for fuelling atrocities will never be held to account.

This July, negotiators at the UN will have a choice but, if they remember what we have all heard in the case of Charles Taylor, they will realise that effective prevention is largely a question of all or nothing.