The report describes Rispens' presentation of Debye, as an opportunist who had no objection to the Nazis, as a caricature.
[I]t can be stated that Debye was rightly called an opportunist after his arrival in the United States. We have seen that he showed himself to be loyal to the dominant political system, first in the Third Reich and then in the United States, while at the same time keeping the back door open: in the Third Reich by retaining his Dutch nationality, in the United States by attempting to secretly maintain some contacts with Nazi Germany via the Foreign Office.
It concludes that Debyes actions in 1933–45 were based on the nineteenth-century positivist view of science which saw research in physics as generating blessings for humankind. The report states that, by his contemporaries, Debye was considered an opportunist by some and as a man of highest character by others. The report asserts that Debye was not coerced by the Nazis into writing the infamous DPG Heil Hitler' letter and that he also did not follow the lead of other societies in doing so but, rather, other societies followed his lead. The NIOD report also concludes that Debye felt obliged to send the letter and that it was, for him, simply a confirmation of an existing situation. The report argues that Debye, in the Third Reich, developed a survival method of ambiguity which allowed him to pursue his scientific career despite the political turmoil. Crucial to this survival method was the need to keep ready an escape hatch, for example in his secret dealings with the Nazis in 1941, if needed.
Yet, the report also states that the picture of Debye should not be oversimplified as Debyes actions were also motivated by his loyalty to his daughter, who had remained in Berlin. In general, Debye developed a survival method of ambiguity, that "could pull the wool over peoples eyes".