On Monday morning, at a hall in the heart of Tokyo’s financial centre, around 600 leading figures from industry, diplomacy and academia gathered for a sumptuous celebration of 100 years of business ties between Japan and France.

Attended by executives of LVMH, Airbus, Dassault and Veolia, the keynote speakers came from that ultimate symbol of Franco-Japanese co-operation — the Renault-Nissan alliance. First up was the Nissan chief executive, Hiroto Saikawa, followed by Renault’s honorary chairman, Louis Schweitzer — the 78-year-old former president who had masterminded the French company’s rescue of Nissan in 1999.

Both speakers knew that behind the scenes, the alliance was in torment, buffeted between controlling ambitions from the French side, seething resentments in Japan and a leader appearing to treat a massive global corporation as his personal fiefdom.