I find the personalisation of international relations quite interesting and wonder if that has always been the case. That leader had to like each other to be able to make better/ more successful business.

Of course the smallest things can start wars. But did Stalin and Churchill like each other when they negotiated, or how about Hitler and Mussolini - or Hitler and Chamberlain.

When those contract negotiations are being discussed it seems to me the personal level of "friendship" is never an issue : The had a chat over a beer, they exchanged sweaters, hand picked .

The first case where I can remember the personal is being discussed i between Charles de Gaulle and Adenauer, then Kohl very extensively, with his "Maennerfreundschaften" to Gorbatschow.

How much of that is real? Is that only an aspect of politicians meeting more often and the connected ability to form "relationships? or is there a greater change in culture?