This year marks the 30th anniversary of the fall of the Berlin Wall. The wall, which stood between 1961 to 1989, came to symbolize the ‘Iron Curtain’ – the ideological split between East and West – that existed across Europe and between the two superpowers, the US and the Soviet Union, and their allies, during the Cold War. How significant was the Berlin Wall during the Cold War – was it more important physically or psychologically?

The Berlin Wall was important physically, as well as psychologically, because Berlin was the only city that was divided physically by the Cold War between the Soviet Union and its allies in the Eastern Bloc and the West.

Given the disparity that quickly emerged between the two sides in economic wealth, freedom of expression and so on, the fear was that, without that wall, there would've been a unification of Berlin in a way that the Soviet side would have lost.

But it was also very important psychologically because it became the symbol of the division between two ideologies that saw each other as inimical to each other.

That meant that if you wanted to visualize the Cold War, and the separation between the capitalist, democratic system of the West and the communist, command-and-control system of the East, Berlin offered a place where you could physically walk from one world, through a checkpoint, into the other. The whole Cold War could be reduced to this one nexus point.

Because of its psychological as well as its physical significance, the fall of the Berlin Wall quickly became the symbol of the collapse of the communist ideology it had shielded.

Since the fall of the Berlin Wall, European countries have reportedly built over 1,000 kilometres of walls – the equivalent of more than six times the total length of the Berlin Wall – along their borders.

Why has Europe been building more walls and how effective have they been? Have they been used more as symbols to appeal to political bases, and if so, has it worked with voters?

The walls that have been built in Europe recently have been for a very specific reason. This was the huge influx of migrants and refugees to Europe in 2015, through what was called the ‘eastern Mediterranean’ or ‘western Balkan route’, from Turkey to Greece and on through the Balkans, Serbia and Hungary to northern Europe – in what was Europe's biggest migrant and refugee crisis since the Second World War.

What’s interesting is that for Viktor Orbán and the Hungarian government, which was on the frontline of the flow of migrants and refugees, building a wall was a way of reasserting its sovereignty. 

Like many other countries along the ‘migrant route’, they resented that the rules under which people could migrate into Europe were flouted by northern European governments which were willing to accept large numbers of migrants and refugees.

By accepting them, they kept attracting more, and so Orbán was worried that, at some point, Germany might say ‘We can’t take anymore’ and they’d be left in Hungary.

It’s important to remember that the communist states of central and eastern Europe were kept in aspic by the Soviet Union – they existed in a hermetically sealed environment without immigration. As a result, they didn’t experience the rise of multicultural societies of the sort that emerged in Britain, Belgium, France and Germany, where immigration persisted throughout the Cold War period.

The countries of central and eastern Europe were delighted that the Berlin Wall collapsed because it allowed them to unify with western Europe. They had been vassal states of the Soviet Union during the Cold War, and by joining the EU, they re-discovered personal freedom and re-gained national sovereignty. They thought they had become masters of their own future again.

But they suddenly found they were on the frontline of a new movement of people that wanted to get into the same world that they’d entered some 15 years earlier. And, as hundreds of thousands of migrants and refugees began arriving, they suddenly realised they were in a union that did not respect their sovereignty.

So, for them, putting up walls was a sovereign act against a European Union that didn’t seem to take their sovereignty seriously.

Has it worked? Definitely. The flow of migrants has been reduced drastically. This is partly because the EU paid Turkey to hold back the over three million migrants based there. But the walls also acted as a physical and psychological deterrent. 

It also worked politically. It allowed Viktor Orbán and other European parties that took the sovereigntist line to strengthen their appeal to voters – voters like to know that governments can do certain things like protecting them and their borders.

What is hypocritical, however, is that many of the governments in western Europe which criticized the Hungarian government for building its wall have actually been rather grateful that they did so as it slowed down the flow of migrants to their countries.

Then there’s the additional hypocrisy of the EU criticizing Donald Trump for building his wall with Mexico when Europeans are benefitting from theirs in Hungary.

Two years before the fall of the Berlin Wall, former US president Ronald Reagan challenged Soviet leader Mikhail Gorbachev to ‘tear down this wall’ declaring ‘across Europe this wall will fall. For it cannot withstand [freedom].’

32 years later, building a wall along the US–Mexico border has become a cornerstone of the current US administration under Donald Trump who has pledged to build a ‘big beautiful wall’. How does this reflect the political evolution of the US and what effect does that have across the rest of the world?

President Reagan talked about tearing down the Berlin Wall as a symbol of the Cold War. He knew that the fall of the wall would undermine the Soviet Union. 

President Trump is way beyond the Cold War. Building a new wall is his response to the growing sense of economic dislocation that segments of America, like Britain and other parts of Europe and the developed world, have experienced on the back of the rise of globalization, which was partly the result of the end of the Cold War but also the rise of China.

The spread of globalization, the declining earning power of many workers in the West, advances in technology which have taken away many high-earning jobs, the eight years of austerity after the global financial crisis – these are all factors driving Trump’s thinking. 

Have inflows of Mexican immigrants or immigrants through the Mexico border been the principal driver of economic insecurity?  No.  What you’ve got is Trump promising to build a wall as a symbol of his administration’s determination to protect Americans.

So I’d say the US–Mexico wall is another symbolic – or psychological – wall. Trump’s wall is supposedly about stopping illegal immigration but there are still plenty of ways to come through the border posts. It’s principally an exercise in political theatre.

From the Great Wall of China to Hadrian’s Wall, walls and fences of all sorts have been used throughout history for defence and security, but not all of them have been physical.

So-called ‘maritime walls’, as well as ‘virtual walls’, are also increasingly being enforced which, today, includes border forces patrolling seas and oceans, such as in the Mediterranean Sea or off the coasts of Australia, and border control systems controlling the movement of people. Politically how do these types of barriers compare to physical ones?

You could argue that the Mediterranean Sea, and the European border forces operating within it, still act as a physical wall because they constitute a physical obstacle to migrants being able to move from the South across the Mediterranean Sea into Europe. 

So I don’t see this maritime wall being much different to the physical walls that have been built to try to stop migrants – just like any other border patrol, the Italian navy is preventing NGO vessels carrying migrants, who have been stranded at sea from docking at Italian ports. 

In this sense, you could argue that the Mediterranean Sea is a larger version of the Rio Grande between the US and Mexico which also incorporates physical barriers along its shores.

I think the more interesting walls that are being built today are virtual walls such as regulatory walls to trade, or with the internet, new barriers are being built to digital communication which affect your capacity to access information. 

In the end, all these walls are manifestations of national sovereignty through which a government demonstrates it can ‘protect’ its citizens – whether they are successful in this objective or not.

The border between Ireland and Northern Ireland, and the presence of enforcement mechanisms along the border, has become a key issue in the Brexit negotiations. How much of the debate over this is about the symbolism of the border against its economic implications?

The Irish border carries great symbolic importance because it reflects the reality of the separation of two sovereign states.

On the island of Ireland, the British and Irish governments have wanted to minimize this reality to the greatest extent possible. They even went as far as removing all types of barriers as part of the Good Friday Agreement.

This is the same sort of fiction the European Union created when it removed any physical manifestations of the existence of borders between those member states in its Schengen agreement on borderless travel.

By removing physical manifestations of the border, the UK was able to reduce some of the popular support for Irish unification as well as support for the IRA’s campaign of violence and terrorism to try to force the same outcome. 

Brexit has thrown a huge spanner into this arrangement. If Brexit is going to mean the entire UK not being in the EU’s customs union then some sort of border would need to be reinstated.

The British government proposed to do all the checks behind the border somewhere. The EU’s view was, ‘Well, that’s nice for you to say, but this border will become the EU’s only land border with the UK, and you cannot guarantee that people won’t be able to smuggle things through.’

On the other hand, recreating a border of some sort, whether physical or not, would reignite the differentiation between the two nations – running counter to the spirit of the Good Friday Agreement.

The only solution available to Prime Minister Boris Johnson has been to put the border down the Irish Sea.  While this means that Northern Ireland will no longer be an obstacle to the UK signing new, post-Brexit, free trade agreements with other countries, it has betrayed the Conservative Party’s unionist allies, for whom it’s essential that the UK’s borders include and not exclude them. 

By the end of the Cold War there were just 15 walls and fences along borders around the world, but today, there are at least 70. How effective, do you think, building barriers are as a political and military strategy to defence and security issues given their financial – and human – cost?

Physical barriers can be an effective form of protection – or imprisonment. 

The separation wall between Israel and the Palestinian territories has reduced the level of terrorist violence being perpetrated in Israel, but the cost has been the impoverishment of many Palestinians, and is another nail in the coffin of a two-state solution.

Yet many Israelis are saying that, maybe, being entirely separate is the best way to achieve peace between the two sides.

However, the walls around the Gaza Strip have not prevented, for various reasons, the Hamas government from developing rockets and firing them into Israel.   

You could argue that the border between China and North Korea, which is severely patrolled, has been a tool of continued political control protecting the Kim Jong-un regime from collapse – as has its virtual border preventing internet penetration.

Similarly, the virtual border the Chinese government has created around its own internet, the ‘great firewall’, has been very effective both economically – allowing Chinese internet platforms to develop without the threat of competition – and also as a form of political control that helps the Chinese Communist Party retain its monopoly on power. 

So walls in all of their shapes and forms can work. They are like sanctions – sanctions are easy to impose but difficult to remove. Walls are easy to build but they’re difficult to break down. 

But my view would be that they still only work temporarily. In the end, walls serve their particular purpose for a particular period, like the Berlin Wall, they end up outliving their purpose.

You have to be alive to the fact that, whether that purpose was a good or bad purpose, there will be a moment when walls end up protecting the interests of an ever-narrower number of people inside the wall, while they cease serving, if they ever did, the interests of the growing number on both sides. 

It’s ironic that the fall of the Berlin Wall in November 1989 was not the main marker of the end of the Cold War. It began earlier that year, with the intensification of people protesting in Poland, Hungary and Czechoslovakia.

Once Hungarian troops dismantled the fence separating them from Austria in May 1989, thousands of Hungarian citizens simply walked out of their country, because by then, the wall between the East and West only existed in their minds.

Then, once East Germans also realized that Mikhail Gorbachev and the Soviet regime had lost its willingness to defend the Berlin Wall, it collapsed. 

So it is interesting that we’re marking the end of the Cold War with this anniversary of the fall of the Berlin Wall, which of course, did divide two halves of one country, making its fall all the more poignant and powerful. But the end of the Cold War really began with the fall of the invisible wall in people’s minds.