A laconic answer

The Lacons lived in a part of Southern Greece called Laconia, and were known for the bravery and the simplicity of their life. One of their rules was always to speak briefly, using no more words than were needed. This was carried so far that to this day, a very short answer is often called laconic.
There was in Northern Greece a land called Macedonia, which was once ruled by a king named Philip. Philip wanted to become master of all Greece. He therefore collected a great army and conquered all Greece, until only Laconia remained unconquered. Then he sent a letter to the brave Lacons saying: "If I invade your country, I will destroy your great city." In a few days an answer came. He found only one word written in it. That word was "If'.