Answer: The phrase "a loss would not be grave" suggests that the consequence of losing something or someone is not significant or serious. In other words, it implies that the impact of the loss would be relatively minor, and not something that would cause significant harm or distress.
For example, if someone were to say, "I lost my old phone, but it's not a big deal since I was planning to upgrade anyway," they are essentially saying that the loss of the phone was not grave because it did not have a major impact on their life.
In general, the phrase "a loss would not be grave" is often used to indicate that while losing something may not be desirable, it is not a cause for great concern or worry.
Explanation: In this context, the phrase "a loss would not be grave" refers to the potential loss of Egypt and the Middle East during a war against an Axis system controlling Europe and most of Africa and Asia. The British Prime Minister, Churchill, is disagreeing with the notion that the loss of Egypt and the Middle East would be a minor setback in the war effort. Instead, he is suggesting that such a loss would be serious and potentially even fatal to the Allied cause. He is highlighting the importance of the United States taking more advanced positions in the conflict in order to tilt the balances in favor of the Allies. In this context, the phrase "a loss would not be grave" means that the consequences of losing Egypt and the Middle East would be significant and potentially catastrophic.