一个是惩罚,一个是批准
sanction（迫使某国服从国际法的）处罚措施,制裁.
penalty更具有一般意义：1.punishment for breaking a law,rule or contract刑罚; 处罚; 惩罚,如there is a penalty for late delivery(有延迟交货的惩罚).
2.thing imposed as a punishment,eg imprisonment or a fine施加的惩罚,如the death penalty（死刑）.