Answer:
Step-by-step explanation:
This statement likely refers to a historical context in which the speaker is suggesting that a guarantee by the British, as opposed to another country, would be less likely to provoke a negative response. The phrase "ancient ally" suggests a long-standing and historically significant relationship between the speaker's country and Britain, which would make a guarantee from Britain more acceptable and less likely to be seen as an aggressive move. The speaker may be expressing gratitude that Churchill reaffirmed this guarantee, indicating that it helped to maintain a sense of stability and reduce tensions in a potentially volatile situation.