I was reading chapter 12. This chapter is based on the story of Joseph.

I am not sure if I understood the story correctly. What I gathered from 12:70 is that Joseph deliberately placed a drinking cup in his brother's bag so that his brother could be retained in his country.

012.070
Falamma jahhazahum bijahazihim jaAAala alssiqayata fee rahli akheehi thumma aththana mu-aththinun ayyatuha alAAeeru innakum lasariqoona
YUSUFALI: At length when he had furnished them forth with provisions (suitable) for them, he put the drinking cup into his brother's saddle-bag. Then shouted out a crier: "O ye (in) the caravan! behold! ye are thieves, without doubt!"
PICKTHAL: And when he provided them with their provision, he put the drinking-cup in his brother's saddlebag, and then a crier cried: O camel-riders! Lo! ye are surely thieves!
SHAKIR: So when he furnished them with their provisions, (someone) placed the drinking cup in his brother's bag. Then a crier cried out: O caravan! you are most surely thieves.
KHALIFA: When he provided them with their provisions, he placed the drinking cup in his brother's bag, then an announcer announced: "The owners of this caravan are thieves."

If my understanding is right, then this leads to a question: Was Joseph's deceptive action acceptable in Islam? He was a muslim (submitter) I believe. Does that mean we can practice deception to achieve higher objectives?

My take was that placing a false blame on someone is an unacceptable act even though if we have a higher good objective in mind. God would not sanction it for muslims under any circumstances.