Answer: In general, the phrase "incident for which the United States Government would be so thankful" suggests that there is an event or situation that would be advantageous for the United States government. The phrase implies that the United States would benefit from the event or situation and would be grateful for it. The context in which the phrase is used can vary, but it generally suggests that the event or situation would help to achieve the goals of the United States government.
Explanation: The phrase "incident for which the United States Government would be so thankful" refers to a situation or event that would be beneficial for the United States government. In the context provided, Winston Churchill is suggesting that involving the United States in the search for the Prinz Eugen would provide an opportunity for the United States to demonstrate their support for the British cause and potentially strengthen the alliance between the two nations. The phrase suggests that the United States would appreciate being involved in such an event or situation.