It was a bitter moment. Defeat is one thing; disgrace is another.
Churchill draws a distinction between losing and being dishonoured by the manner of the loss. Defeat can result from superior enemy strength, adverse circumstances or strategic failure, and does not necessarily imply moral blame. Disgrace, by contrast, suggests that conduct, judgement or responsibility has fallen below an expected standard.
In reflecting on the fall of Tobruk, Churchill presents the event as more than a military setback. His wording conveys the sense that the loss carried implications for reputation, leadership and national confidence. The distinction is important because it separates an unfavourable outcome from the character or quality of the actions that produced it. More broadly, the quotation can be applied to situations where failure itself is not shameful, but negligence, dishonesty or abandonment of responsibility may be. It therefore invites judgement not only of results, but also of the conduct and decisions behind them.