Final answer:
When Chamberlain sees the hole knocked in the line, it refers to the Munich Agreement in 1938, where Chamberlain, as the British Prime Minister, negotiated with Adolf Hitler over the annexation of certain areas of Czechoslovakia. The result was the Munich Pact, which solidified appeasement but was later criticized for leading to war.
Step-by-step explanation:
When Chamberlain sees the hole knocked in the line, it refers to the Munich Agreement in 1938. Chamberlain, as the British Prime Minister, took the lead in negotiating with Adolf Hitler over the annexation of certain areas of Czechoslovakia.
After much negotiation, Chamberlain and other leaders agreed to allow Germany to annex these areas. The result was the Munich Pact, which solidified the policy of appeasement and temporarily prevented an upcoming war.
However, this policy was heavily criticized by Winston Churchill, who warned that it would lead to war. It eventually did, as Hitler continued to make demands and showed no signs of stopping.