What are the reasons for Cooper’s ambivalence in the novel’s setting and title of “neutrality?”
I don't think that Cooper is ambivalent about the setting of the novel, but rather is willing to accept that there is ambiguity within the complex reality of war. Cooper understands the condition of the setting. In The Spy: A Tale of Neutral Ground, Cooper suggests that the world of espionage and the nuances of war are far from static and defined. War forces issues of ambiguity and complexity. While the overall goal might be exact and clear, achieving it is a delicate process. Cooper is able to assert that Colonial independence is an absolute good. However, the work that men like Harvey Birch must undertake are critical in the achievement of such an end.
The setting in which most of the novel takes place is "neutral territory." Loyalist forces and Patriotic forces intermingle without a clear stronghold in the area of neutrality. Critical locations of the novel's setting emerge in Neutral Ground. For example, The Locusts is situated in the midst of this Neutral Ground. The use of such a setting helps to enhance Cooper's main idea that domains of political ambiguity are critical in achieving the end political goal. One cannot simply cling to "familiar" territories in order to achieve a larger political goal. Such a setting allows Cooper to present a "pattern of moral contrasts" in his writing. This emphasizes the larger issue of how challenging of a terrain war is from a moral and political point of view. Cooper does not hold ambivalence about this, but rather is willing to explore its ambiguity to make a statement about war, in general.
Cooper finds it easy to lionize the heroes like George Washington in The Spy: A Tale of Neutral Ground. Washington and heroes like him are not the dominant forces in war. Cooper brings attention to a challenging element to depict in the war setting. The spy and the realm of espionage are critical elements in warfighting. The work that Harvey Birch does is not sensationalist and does not make headlines. Yet, his ability to generate and transmit intelligence on the ground is how wars are won. The American Revolution was pure in its end, but it could only be accomplished through the nuanced and delicate efforts of people in the realm of espionage. In bringing attention to this aspect of war, Cooper brings out the challenges intrinsic to such endeavors. The neutrality to which Cooper alludes in the title helps to illuminate this condition. "The Spy" himself is always on ground that has to be seen as neutral. The spy, seeking to "come in from the cold," is poised between two worlds and must always stand on shifting and fluid ground. To divulge too much puts the spy in a vulnerable position in much the same way as not divulging enough. This movement is dramatic in its scope and allows Cooper to depict his hero in such a politically and emotionally driven manner. Such a conflict helped to enhance the drama of the piece and enabled Cooper to increase the appeal of his work.