I gave up my career in banking

to try to make the world a safer place.

This involved a journey into national and global advocacy

and meeting some of the most extraordinary people in the world.

In the process, I became a civil society diplomat.

Civil society diplomats do three things:

They voice the concerns of the people,

are not pinned down by national interests,

and influence change through citizen networks,

not only state ones.

And if you want to change the world, we need more of them.

But many people still ask,

"Can civil society really make a big difference?

Can citizens influence and shape national and global policy?"

I never thought I would ask myself these questions,

but here I am to share some lessons

about two powerful civil society movements that I've been involved in.

They are in issues that I'm passionate about:

gun control and drug policy.

And these are issues that matter here.

Latin America is ground zero for both of them.

For example, Brazil --

this beautiful country hosting TEDGlobal has the world's ugliest record.

We are the number one champion in homicidal violence.

One in every 10 people killed around the world is a Brazilian.

This translates into over 56,000 people

dying violently each year.

Most of them are young, black boys dying by guns.

Brazil is also one of the world's largest consumers of drugs,

and the War on Drugs has been especially painful here.

Around 50 percent of the homicides in the streets in Brazil

are related to the War on Drugs.

The same is true for about 25 percent of people in jail.

And it's not just Brazil that is affected by the twin problems of guns and drugs.

Virtually every country and city across Central and South America is in trouble.

Latin America has nine percent of the world's population,

but 25 percent of its global violent deaths.

These are not problems we can run away from.

I certainly could not.

So the first campaign I got involved with started here in 2003

to change Brazil's gun law

and to create a program to buy back weapons.

In just a few years,

we not only changed national legislation

that made it much more difficult for civilians to buy a gun,

but we collected and destroyed almost half a million weapons.

This was one of the biggest buyback programs in history --

(Applause) --

but we also suffered some setbacks.

We lost a referendum to ban gun sales to civilians in 2005.

The second initiative was also home-grown,

but is today a global movement to reform the international drug control regime.

I am the executive coordinator

of something called the Global Commission on Drug Policy.

The commission is a high-level group

of global leaders brought together to identify more humane

and effective approaches to the issue of drugs.

Since we started in 2008, the taboo on drugs is broken.

Across the Americas, from the US and Mexico to Colombia and Uruguay,

change is in the air.

But rather than tell you the whole story about these two movements,

I just want to share with you four key insights.

I call them lessons to change the world.

There are certainly many more,

but these are the ones that stand out to me.

So the first lesson is:

Change and control the narrative.

It may seem obvious,

but a key ingredient to civil society diplomacy

is first changing and then controlling the narrative.

This is something that veteran politicians understand,

but that civil society groups generally do not do very well.

In the case of drug policy,

our biggest success has been to change the discussion

away from prosecuting a War on Drugs

to putting people's health and safety first.

In a cutting-edge report we just launched in New York,

we also showed that the groups benefiting most from this $320 billion market

are criminal gangs and cartels.

So in order to undermine the power and profit of these groups,

we need to change the conversation.

We need to make illegal drugs legal.

But before I get you too excited,

I don't mean drugs should be a free-for-all.

What I'm talking about, and what the Global Commission advocates for

is creating a highly regulated market,

where different drugs would have different degrees of regulation.

As for gun control, we were successful in changing,

but not so much in controlling, the narrative.

And this brings me to my next lesson:

Never underestimate your opponents.

If you want to succeed in changing the world,

you need to know who you're up against.

You need to learn their motivations and points of view.

In the case of gun control,

we really underestimated our opponents.

After a very successful gun-collection program,

we were elated.

We had support from 80 percent of Brazilians,

and thought that this could help us win the referendum

to ban gun sales to civilians.

But we were dead wrong.

During a televised 20-day public debate,

our opponent used our own arguments against us.

We ended up losing the popular vote.

It was really terrible.

The National Rifle Association -- yes, the American NRA --

came to Brazil.

They inundated our campaign with their propaganda,

that as you know,

links the right to own guns to ideas of freedom and democracy.

They simply threw everything at us.

They used our national flag,

our independence anthem.

They invoked women's rights

and misused images of Mandela, Tiananmen Square, and even Hitler.

They won by playing with people's fears.

In fact, guns were almost completely ignored in their campaign.

Their focus was on individual rights.

But I ask you,

which right is more important,

the right to life

or the right to have a gun that takes life away?

(Applause)

We thought people would vote in defense of life,

but in a country with a recent past of military dictatorship,

the anti-government message of our opponents resonated,

and we were not prepared to respond.

Lesson learned.

We've been more successful in the case of drug policy.

If you asked most people 10 years ago if an end to the War on Drugs was possible,

they would have laughed.

After all, there are huge military police prisons

and financial establishments benefiting from this war.

But today, the international drug control regime is starting to crumble.

Governments and civil societies are experimenting with new approaches.

The Global Commission on Drug Policy

really knew its opposition,

and rather than fighting them,

our chair -- former Brazilian President Fernando Henrique Cardoso --

reached out to leaders from across the political spectrum,

from liberals to conservatives.

This high level group agreed to honestly discuss

the merits and flaws of drug policies.

It was this reasoned, informed and strategic discussion

that revealed the sad truth about the War on Drugs.

The War on Drugs has simply failed across every metric.

Drugs are cheaper and more available than ever,

and consumption has risen globally.

But even worse,

it also generated massive negative unintended consequences.

It is true that some people have made these arguments before,

but we've made a difference

by anticipating the arguments of our opponents

and by leveraging powerful voices

that a few years ago would probably have resisted change.

Third lesson: Use data to drive your argument.

Guns and drugs are emotive issues,

and as we've painfully learned in the gun referendum campaign in Brazil,

sometimes it's impossible to cut through the emotions

and get to the facts.

But this doesn't mean that we shouldn't try.

Until quite recently,

we simply didn't know how many Brazilians were killed by guns.

Amazingly, it was a local soap opera called "Mulheres Apaixonadas" --

or "Women in Love" --

that kicked off Brazil's national gun control campaign.

In one highly viewed episode,

a soap opera lead actress was killed by a stray bullet.

Brazilian grannies and housewives were outraged,

and in a case of art imitating life,

this episode also included footage of a real gun control march

that we had organized right here,