This blog is an unedited version of the speech delivered by Bill Gates at the Royal United Services Institute (Rusi) in London on Wednesday 19 April
It is an honour to be here. I particularly want to recognise Lord Hague and Ruth Davidson for being here today at a very busy time for British politics.
2017 has already seared some painful images into our minds. The terrorist attack outside of Parliament. Children writhing from chemical attacks in Syria - and starving in Yemen and East Africa. The continued despair and desperation of refugees.
If we base our worldview on what we see in the headlines and on the news, it's easy to conclude that things are getting worse.
But a headline is not the same thing as a trendline.
And the data makes a very different case. Viewed through the lens of data, our world is far better than it has been for most of humanity.
The question is whether we build on that progress, or allow the forces of uncertainty and fear to slow or reverse it.
I - as you might guess - believe we must build.
And part of the reason why is because of what we have accomplished already.
In 1930, only three out of 10 people could read. Today, more than eight in 10 are literate. By the turn of the century, there will be almost no one without a formal education.
As recently as 1950, three quarters of the world was still living in extreme poverty. Today, that number is down to less than 10%.
In 1990, one in ten children died before age five, almost entirely of preventable causes. Today, that number is lower than one in 20. In the next fifteen years, it will be one in 40.
These remarkable achievements are the result of a unique convergence. Industrialization and technological innovation have led to greater productivity and prosperity. Scientific advancement has made it possible for people to live healthier, longer lives. And the growth of capitalism, free markets, and trade has pulled more families into the middle class.
Foreign aid also has been critical to this progress. It has ensured that as humanity makes these leaps, the benefits extend to everyone.
And, in doing so, it has broken the cycle of extreme poverty and disease that has trapped so many for so long.
Still, those who do not realise how much progress has been unlocked worry that aid is a waste or that it only benefits people in some faraway place.
The truth is that investing in the health and wellbeing of people in a poor country pays dividends far beyond that country's borders. The UK's foreign aid investments are, in fact, long term investments in the health and security of British citizens here at home.
It concerns me that some world leaders are misinterpreting recent events as reasons to turn inward instead of seeing them for what they are: problems that can be solved... if we invest in their solutions.
That's the case I want to make in my time with you today.
If I could pick just one number that highlights the effectiveness of development aid, it would be 122million. That's the number of children's lives saved since 1990.
Saving children's lives is the best investment you can make in foreign aid because almost all advances in society - better health, education, economic growth - show up as gains in the childhood mortality chart.
If you're reducing child deaths, you're laying the foundation for greater prosperity and stability. It also leads to many downstream benefits, as I'll mention in a bit.
So, what is the biggest reason for the drop in childhood mortality? It is surprisingly simple. More children in poor countries are getting the basic package of vaccines that every child in the UK has been getting for years.
Every dollar spent on childhood immunizations saves $16 in health care costs and productivity losses. And when you consider the broader economic impact of disease and illness, vaccines return $44 for every dollar invested. That's money developing countries can invest in better nutrition for kids, new health clinics, and schools.
The UK government has long understood the value of immunizations. Seventeen years ago, we worked together to create Gavi, the Vaccine Alliance that make sure children in poor countries are immunized against vaccine preventable diseases.
Through DfID's contribution to Gavi, UK taxpayers have prevented two million deaths and will save the lives of over a million more children in the next four years.
Gavi is an example of the kind of innovative, multilateral approach to development aid that DfID and our foundation have invested in together because it has proven time and again to work. Let me give you a few other examples.
The UK and our foundation have been big supporters of The Global Fund, which works with developing countries to prevent and treat deadly infectious diseases like HIV, TB, and malaria. Between now and 2020, the UK's support will save more than two million lives.
Because of the UK's investment in the Global Polio Eradication Initiative, 1.6million people who would otherwise have been paralysed by polio are living normal lives - and we are now on the verge of eradicating this highly infectious disease forever.
The UK also has been a leader in the campaign to rid the world of neglected tropical diseases. Though virtually unknown in wealthy countries, these diseases - with names like elephantiasis and African sleeping sickness - have caused unimaginable suffering for hundreds of millions of people in the developing world.
Five years ago, the UK hosted a meeting here in London with the world's pharmaceutical companies and other backers who pledged to eliminate or control 10 of the worst neglected diseases. I was just in Geneva, where we gathered to take a measure of the progress. It's pretty amazing.
We are reaching nearly a billion people a year with treatments for these terrible diseases. That is a scale and reach unmatched in the history of public health. The UK has underscored the value of this effort with a new commitment that will protect more than 200million people in the next four years from the suffering caused by treatable tropical diseases.
So, what is it that these aid initiatives have in common?
First, they build on the best of what we have learned about what works in foreign aid.
Second, by pooling the resources and aligning the interests of both wealthy and poor countries -
they show that everyone is pulling from the same end of the rope.
Third, they keep overhead costs to a minimum, while leveraging the expertise of skilled professionals in organizations like DfID and the World Health Organization.
Fourth, they encourage private sector involvement, which is vital to ensure that poor countries have access to high quality, affordable health products.
The point is, aid works. And, as I mentioned, it also has tangible benefits at home. For example, aid reduces the threat of deadly pandemic diseases that could spread as quickly across Western Europe as Ebola did in West Africa three years ago.
Whether the next epidemic is unleashed by a quirk of nature or the hand of a terrorist, scientists say a fast-moving airborne pathogen could kill more than 30million people in less than a year.
A disease is more likely to become an epidemic when countries are unstable and have no functioning health system. And a health crisis somewhere is a health crisis everywhere.
We can't build a wall to hold back the next global epidemic. We need to combat it - and the underlying socioeconomic problems - at the source.
This is what foreign aid does.
Military leaders like those in this room understand this - that aid makes vulnerable parts of the world less prone to conflict and collapse.
When Secretary of Defense James Mattis was a senior commander in the US military, he once told Congress: "If you don't fund the State Department fully, then I need to buy more ammunition."
Nine senior British military officials reinforced this point in 2013 when they wrote that the coupling of defense spending and foreign aid - the combination of hard and soft power - "is one of the UK's greatest strategic assets."
Foreign aid also is a key factor in helping poor countries become self-sufficient.
Take child health, for example. When people no longer have to worry if their children will survive into adulthood, they decide to have fewer children.
As family size drops, it gets easier for countries to feed, educate, and provide opportunity for their people.
These benefits are compounded when women can plan and space their births. Yet, even today, millions of women in the developing world don't have access to modern contraceptives.
Solving this problem is another area where the UK has been a leader. Five years ago, DfID hosted a summit here in London that launched a global effort to reach an additional 120million women and girls with family planning services.
This summer, my wife, Melinda, will co-host another summit here to ensure that the world delivers on this promise. This will be yet another moment where British leadership will help make the lives of women and girls around the world better.
Some people make the argument that foreign aid will be needed forever. To the contrary, smart aid enables countries to take ownership of their future by encouraging investment in things like better schools, health care, and agriculture - the building blocks of a better, self-sufficient future.
Just as the Marshall Plan helped Europeans rebuild the continent themselves after World War II, targeted aid today helps countries lift themselves out of poverty and chart their own future.
Still, when it comes to aid, just like any other investment, it's good to keep an eye on it.
As someone who puts $5billion a year toward development aid, I have a strong interest in making sure that money is well spent. This is especially true because half of that $5billion comes from Warren Buffet, who hates wasting money even more than I do.
I also have a strong interest in making sure our partners - especially our closest partners like DfID - are getting a good return on their investment. Because that's the only way we'll achieve our shared ambition of a world where the poorest countries can stand on their own.
Given the recent wave of newspaper stories suggesting the UK's aid money isn't being well spent, I feel it is important for someone like me who works on foreign aid every day to make the case for the facts.
So, let me be clear.
When aid is mismanaged it is a double crime - stealing both from the taxpayer and from the poor.
Secretary Patel has been very clear that any waste is unacceptable - and that DfID's partners must deliver results. And she has promised that where there have been mistakes, DfID will make changes.
But let's also be realistic. It will never be possible to eliminate small-scale corruption or waste entirely, any more than we could eliminate waste from every government program - or from every business, for that matter.
It is also worth noting that the British government has courageously taken up the difficult but vital challenge of working in the most fragile countries - because these are often the areas of greatest need.
Making these countries more stable makes the world safer - but it is not an easy task. As the people in this room know better than most, fragile states are places where it is very difficult to operate.
Yet, even with these challenges, DfID is widely recognized as one of the most effective, efficient, and innovative aid agencies in the world. I have seen the impact of DfID's work on the ground, and I wish all British taxpayers could, too. You are the reason that malaria deaths are down in entire villages, and lifesaving vaccines are now reaching kids in the most remote areas of the world.
Make no mistake. My foundation and I expect results. It is for exactly that reason that I have chosen to invest our foundation's resources - over and over again - working alongside DfID. Because in DfID we see a kindred organisation that believes in rigor, results, and outcomes.
I have also seen calls by some newspapers and politicians to abandon the UK's cross-party commitment to spend 0.7% of its Gross National Income on international development.
The 0.7% was first set out by the UN in 1970 as a framework for wealthy countries to work together to reduce extreme poverty. It has been discussed, debated, and affirmed many times since.
Maintaining the 0.7% commitment provides developing countries with the predictability they need to budget and plan. This is important so they know if they will have the resources necessary to deliver essential services like keeping hospitals open, getting babies their vaccinations, and ensuring that children have the nourishment they need to succeed in school.
The Prime Minister made clear in her January visit to the US, and more recently in a speech in Scotland, that she sees the 0.7% aid commitment as a critical pillar of Britain's foreign policy.
In my view, Britain should be praised, not ridiculed, for sticking to this commitment. It was a well-considered decision that sets an example for other wealthy Western countries.
It also is visible proof of the UK's goodwill and humanity. Withdrawing aid would cost lives - which is reason enough to continue it. But it would also create a leadership vacuum that others will fill, undermining the UK's influence in these regions.
It is reassuring to know that as Britain prepares to leave the European Union, it will not step back from the world.
As people who will help shape foreign policy in a post-Brexit Britain, I hope that you will speak up for aid as a vital national interest that is essential to ensure a more stable world.
As the Prime Minister said recently, British aid speaks strongly to the values that have long defined Britain as a beacon of hope and optimism. A country that will never turn its back on those in need. And a country that will always meet its commitments - especially to the most vulnerable.
This kind of leadership, and the leadership of people like Lord Hague, Ruth Davidson and MPs from all parties, is what will assure a more secure and prosperous future for Britain and for people everywhere.
Correction: This blog previously stated that UK foreign aid will "save the lives of over a million more children in the next four years". This number will saved over the next four years.