After decades of separate development and a decade of trying to reform apartheid, his government had concluded, at the end of the 1980s, that the challenge was not how South Africans from different ethnicities should live apart: “It was what we needed to do to enable them to live together in mutual respect and harmony”.

We were ready to embark on fundamental constitutional transformation – but in so doing how would we be able to ensure that none of our ethnic groups would be submerged by the majority?

We believed that this question could be dealt with by negotiating a strong constitution”.

My party favoured a power-sharing model – similar to that of Switzerland – in which there would have been maximum autonomy for our constituent communities. We wanted mechanisms that would have assured inclusivity – but not a veto – for minorities in the processes of government – such as the idea of a rotational presidency and a multi-ethnic state council. Unfortunately, we were not successful and ended up with a majoritarian system.

The new South African Constitution had nevertheless made full provision for the accommodation of diversity. It recognised 11 official languages and proclaimed that they should enjoy parity of esteem.

Unfortunately, according to De Klerk, virtually every one of these provisions had been ignored or diluted since the adoption of the Constitution in 1996.

De Klerk said that throughout the world populations were becoming more cosmopolitan:  the world’s 200 countries now included more than 6 000 different cultural communities.  More than 130 countries had minorities comprising more than 10% of their populations.

Everywhere people were on the move – and everywhere they were confronting once homogenous societies with new challenges.

De Klerk said that the inability of countries to manage diversity had become by far the greatest source of conflict in the world. “The simple reality is that in the 21st century, the main threat to peace no longer comes from of wars between countries: it comes from the growing threat of conflict within countries between ethnic, cultural and religious communities.

The accommodation of diverse immigrant groups had become one of the most controversial issues in Europe.  It had played a decisive role in recent elections in a number of European countries.  It had led to ugly reaction and riots and was a major factor in the British decision two years ago to leave the European Union. As Italians understood, the arrival of indeterminate numbers of refugees was creating unsustainable human and logistic problems.

The European Union was confronted by the challenge of striking a balance between core humanitarian values and political reaction.  It also had to take into consideration the need to facilitate the immigration of sorely-needed skilled workers – necessitated by the expected decline of its workforce by 20 million people by 2030.

Immigration and demographics had also played a central role in the 2016 election of President Donald Trump.  Trump supporters feared that the traditional European-descended dominance of the United States was under threat from changing demographics – and particularly from the emergence of Hispanic Americans as the country’s largest ethnic minority. Hispanics would include more than 100 million people – or one in four Americans – by 2050.  Already they made up more than a third of the populations of Texas and California and more than 40% of the population of New Mexico. But should they accept the convention that all migrants should eventually become English-speaking – or would the United States increasingly have to accept bilingualism and multi-lingualism?

De Klerk said that, as South Africa had discovered, the answer to diversity was not secession, partition and devising ways to enable communities to live apart.  It was to adopt approaches and to establish norms that would enable different cultural and ethnic communities to live together peacefully and in mutual respect within the same states.  To achieve this, the international community had to reach broad agreement on the cultural, linguistic and educational rights that such communities should enjoy. It needed to do much more to define and protect the rights of cultural, ethnic and religious minorities throughout the world.

We need to establish an international norm for these rights, just as we have already done for individuals, for women and for children.

We need to promote acceptance of the role that education can and must play in the preservation of religious, cultural and language diversity.”

We need to measure the behaviour of governments against these norms.

De Klerk concluded by observing that we had entered the global village. “It is exciting; it is often very confusing; and sometimes a little frightening…The presence of people from so many different cultures is one of the most enriching aspects of our new world.  But it will also require us to observe new codes of behaviour and to respect the multidimensional cultural, religious and linguistic identities and rights of people.