Via Jimmy Akin
It's 346 B.C. and King Philip II of Macedon (father of Alexander the Great) has just subjugated a bunch of Greek city-states.
He then approaches Sparta and sends them a message: "You are advised to submit without further delay, for if I bring my army into your land, I will destroy your farms, slay your people, and raze your city."
The Spartans reply: "If."