Tim Marshall is one of the world’s most successful authors on foreign affairs. He’s the writer who put the ‘geo’ into geopolitics with his multi-million selling books Prisoners of Geography and The Power of Geography.

Marshall’s principal argument is that without geography we cannot understand the world. Geography explains why Vladimir Putin wanted to annex Crimea; to remain a world power, Russia needs to maintain a navy and since Russian ports are frozen for half the year, Putin wants to control the warm water port of Odessa.

Geography also explains why China would find it highly difficult to invade Taiwan. The Taiwan Strait is about 130 km wide at its narrowest point, which is roughly three times the distance from Dover to Calais. Any invading force would face inhospitable coastlines, unpredictable monsoons and muddy, tidal beaches. Beijing might decide in time that these are risks worth taking. But these basic and immutable facts of natural terrain still matter hugely in international affairs.

On October 22 Marshall comes to the Intelligence Squared stage just weeks out from the pivotal election in the United States to discuss how politics and geography intersect on the world stage. He will help us understand what's at stake for the world in 2024 and how geography will underpin the geopolitical conflicts of the future.