A proverb literally meaning "to deceive the enemy, first deceive your allies." It implies using deception within one's own side to mislead opponents and is often used sarcastically or critically.
彼は冗談めかして「敵を欺くにはまず味方から」と言ったが、誰も笑えなかった。
He jokingly said "to deceive the enemy, first deceive your allies," but no one could laugh.
政治の世界ではこのことわざを引き合いに出して、裏切りを批判することがある。
In politics, this proverb is sometimes cited to criticize betrayals.
小説の中で、将軍は「敵を欺くにはまず味方から」と命じて偽情報を流した。
In the novel, the general ordered to "deceive the enemy by first deceiving his allies" and spread false information.