Is it permissible to take a fee or a percentage of money in exchange for guaranteeing a person with a foreign bank for importing goods into a country that is not secure, given the risk of financial loss for the guarantor?

It is impermissible for someone who opens a line of credit in their name to take a fee from the beneficiary, because they are a guarantor, and a guarantor is not allowed to take a fee for their guarantee, as this is considered a loan that draws a benefit. If the guarantor repays the debt, they are then owed the equivalent of what they repaid by the debtor, and they are like a lender who is not permitted to take compensation or benefit. The prohibition becomes more severe if the terms of the bank's credit are usurious, and the guarantee is not permissible even if no benefit accrues to the guarantor.