Read the following excerpt from Winston Churchill's "Their Finest Hour" speech: Here is where we come to the Navy — and after all, we have a Navy. Some people seem to forget that we have a Navy. We must remind them. For the last thirty years I have been concerned in discussions about the possibilities of oversea invasion, and I took the responsibility on behalf of the Admiralty, at the beginning of the last war, of allowing all regular troops to be sent out of the country. That was a very serious step to take, because our Territorials had only just been called up and were quite untrained. Therefore, this Island was for several months particularly denuded of fighting troops. The Admiralty had confidence at that time in their ability to prevent a mass invasion even though at that time the Germans had a magnificent battle fleet in the proportion of 10 to 16, even though they were capable of fighting a general engagement every day and any day, whereas now they have only a couple of heavy ships worth speaking of — the Scharnhorst and the Gneisenau. We are also told that the Italian Navy is to come out and gain sea superiority in these waters. If they seriously intend it, I shall only say that we shall be delighted to offer Signor Mussolini a free and safeguarded passage through the Strait of Gibraltar in order that he may play the part to which he aspires. There is a general curiosity in the British Fleet to find out whether the Italians are up to the level they were at in the last war or whether they have fallen off at all.
Analyze the effectiveness of this excerpt. How does it function within the speech as a whole? How does the structure of the excerpt help to convey the speech's purpose and arguments? Support your argument with evidence from the speech.