Question: Who predicted Germany's declaration of war against the United States months before?
Sentence: This is widely agreed to be a grand strategic blunder, as it abrogated the benefit Germany gained by Japan's distraction of the U.S. (predicted months before in a memo by Commander Arthur McCollum)[nb 12] and the reduction in aid to Britain, which both Congress and Hitler had managed to avoid during over a year of mutual provocation, which would otherwise have resulted.
Answer in sentence: yes