paper tiger (指人、国家或局势)纸老虎，外强中干者，貌似强大而实质虚弱的敌人

【例句】
Your husband acts tough, but he's really a paper tiger.
你丈夫看似强硬，实际上只是一个纸老虎。

Don't be afraid of that bully. He's nothing but a paper tiger.
你用不着怕那个欺负弱小的人，他只是一只纸老虎。