How is the political environment in Belfast conducive to the girls' investigation in the book, The File on Fraulein Berg?

The political environment of wartime Belfast is a great influence on the girls and their subsequent actions. The girls know nothing about Fraulein Berg except that she is German, and in 1944 Belfast, that is enough to arouse suspicion—especially in naive thirteen-year-olds. These girls have been conditioned to believe that they must support their country above all else, and that anyone German poses a threat to their country's freedom. Embracing the patriotic loyalty they have been taught to embrace and believing that all Germans are enemies, the girls quickly condemn the new teacher. Harriet takes the condemnation a step further and labels her a spy.