Mini strategy series @soerenbax: The #ThirtySixStratagems, a collection of ancient Chinese military thought and experience.
Characters of the second of Thirty-Six Stratagems: 围魏救赵 (圍魏救趙) – Wéiwèijiùzhào. 围, wéi: surround, enclose. 魏, wèi: Wei (family name). 救, jiù: save, rescue, help. 赵, zhào: Zhao (family name).
Meaning: Besiege Wei to save Zhao. Your friend and ally may besiege the home base of your opponent after his forces left to attack you. Thus finding and attacking the weak and exposed flank of your attacker. The opponent will fight on two fronts, which increases the chance of victory.
Business example: When a strong group (aggressor) is about to take over a weaker group (defender), then a third party may gain a good reputation by attacking the aggressor in apparent behalf of the defender. The third party may succeed to eventually take over both parties without the nasty side effects of outright aggression.