Cockcroft missed Kurchatov's visit because he had left for the US to press for declassification of the fusion work, as there was now widespread belief on both sides of the Atlantic that sharing their findings would greatly improve progress.
Cockcroft missed Kurchatov's visit because he had left for the US to press for declassification of the fusion work, specifically to avoid this sort of duplication of effort. Their was widespread belief on both sides of the Atlantic that sharing their findings would greatly improve progress.