Former Soviet Union leader Nikita Khrushchev once said to former US President Richard Nixon, “If the people believe there’s an imaginary river out there, you don’t tell them there’s no river there. You build an imaginary bridge over the imaginary river.”

Ironically it was Mr Khrushchev who, previously under the US presidency of John F. Kennedy, called for the construction of the Berlin Wall which would divide Germany between 1961 and 1989. He later described the wall as a “hateful thing”, but said it was the only option to halt the flow of East Germans to the West.

Walls provide practical as well as psychological barriers. They tell us a lot about the times and context in which they are built, maintained, dismantled; about the lack, or emergence, of spirit of generosity.

The general western consensus of the last two decades was that a softening of national borders was a good thing; in so many ways, not least economically, we depend on each other. America in particular long prided itself as leading the free world, building bridges and tearing down walls.

That worldview ended this week when US President Donald Trump unveiled his plan to build what he calls a “beautiful” wall along the Mexico-US border. “A nation without borders is not a nation,” he says.

Last year, Mr Obama urged the next generation of leaders in Northern Ireland to forge a new identity, to recognise “the humanity of those on the other side of the argument.”

Whereas the Berlin Wall sought to prevent Berliners from leaving the communist East for the capitalist West, America seeks to prevent Mexicans – or certain Mexicans – from entering altogether.

In Northern Ireland we have our own kind of dividing wall, though smaller and numerous builds replicated across certain areas. Termed “peace walls”, they do more than prevent crossing between the Protestant/British loyalist community on one side and Catholic/Irish nationalist community on the other. They thwart street violence and forge a sense of stability amongst those on either side.

These walls were first erected in 1969 with the onset of the conflict. Almost twenty years on from the 1998 Good Friday peace agreement they still stand, bearing countless signatures and messages of goodwill planted by locals and visitors from across the world.

Last weekend’s Irish Times described Donald Trump’s inauguration as “the day humility died.”

Mr Trump’s moves to build a “beautiful” wall come in stark contrast to the words of his predecessor Barack Obama when he visited Northern Ireland in 2013; he said a new generation “despite resistance, despite setbacks, despite hardship, despite tragedy… have to remind us of the future again and again and again.”

Last year, Mr Obama urged the next generation of leaders in Northern Ireland to forge a new identity, to recognise “the humanity of those on the other side of the argument.”

Last weekend’s Irish Times published “A New York Times take on Trump’s inauguration: the day humility died.” As it begins work on constructing a wall on its own doorstep it seems America’s generosity of spirit has died too.

Rather than focusing on walls we could focus more on building bridges than bring us together.

What was once perceived “hateful” is now “beautiful”. In Northern Ireland, few would describe peace walls as such. Peace, psychological security and solidarity they might bring, but little else.

If the fall of the Berlin Wall brought about the reawakening of freedom, the tone set by Mr Trump’s presidency thus far suggests a much darker epoch.

The continued existence of Northern Ireland’s walls raises questions of our own context; our fear of the unknown and change. Rather than focusing on walls we could focus more on building bridges that bring us together. That, of course, will require humility and generosity of spirit on both sides.