The clip below of the Battle of Wits scene from [The Princess Bride](https://en.wikipedia.org/wiki/The_Princess_Bride_(film)) ([IMDB](https://www.imdb.com/title/tt0093779/)), the character Vizzini (Wallace Shawn) says:

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> You’ve fell victim to one of the classic blunders! The most famous is never get involved in a land war in Asia, but only slightly less well known is this; never go in against a Sicilian, when death is on the line! Aha ha ha ha… (and then keels over, dead.)
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What does the line "never get involved in a land war in Asia" refer to? I don't understand the reference. *Does it connect to the plot in some way I'm missing*, or is it completely unrelated?