The conference tried to redraw the world in a few crowded months

MacMillan stresses just how compressed and overloaded the Paris conference was: delegations from dozens of nations descended on the city simultaneously, each pressing competing claims about borders, minorities, and historical grievances, while the national leaders themselves were also trying to run their own countries by cable from hotel suites. The sheer number of unresolved questions — from the fate of the Ottoman territories to the borders of new states carved out of Austria-Hungary — meant that no single issue received the sustained attention it deserved.

She shows how this compressed timeline forced improvisation: experts were consulted piecemeal, maps were redrawn overnight, and decisions that would shape a region's stability for a century sometimes got settled in a single afternoon meeting between three or four men. The scale of the task was arguably impossible to do well under any circumstances, let alone in the exhausted aftermath of a war that had just killed millions.

Takeaway: judging historical decisions fairly requires accounting for the sheer volume of simultaneous, irreducible complexity decision-makers faced, not just the outcome with hindsight.