只因少了一颗钉 只因少了一颗钉英語For Want of a Nail是一首韵文说明小的行动可能会导致大后果最早可能源於世紀日耳曼地區詩人佛萊登英语Freidank的作品 For Want of a Nail For want of a nail the shoe was lost 少了釘子失了蹄鐵 For want of a shoe the horse was lost 少了蹄鐵失了戰馬 For want of a horse the rider was lost 少了戰馬失了騎士 For want of a rider the message was lost 少了騎士失了情報 For want of a message the battle was lost 少了情報失了勝仗 For want of a battle the kingdom was lost 少了勝仗失了王國 And all for the want of a horseshoe nail 這全因少了個馬蹄釘