What is the ruling of Islamic law concerning a sister who withdrew funds by proxy from her brother to establish a project agreed upon between them, then halted the project fearing excessive expenses and the anger of her brother and her husband, and her brother is now demanding the full return of the funds at the current exchange rate?

The mistake lies in closing the project without consulting the brother, and an apology based on fear of project failure is unacceptable after the actual commencement and receipt of money. This constitutes a type of transgression that necessitates compensation equivalent to the brother's loss. The brother is not entitled to claim all the money he invested in the project; rather, he is entitled to compensation commensurate with the transgression. It is advisable to refer the matter to experts to assess the losses incurred due to the project's closure, which would then become a debt, while striving for reconciliation between the parties and involving well-intentioned individuals to mediate.