My accountant has always said, so long as I get a receipt/invoice that corresponds to the transaction, and the company/country isn't knowingly sanctioned, and the services rendered were licit and bonafide, its all good.
This is my US-based accountant for my US-based corporation, but I'm sure it translates well.
Yep, all you really want is plausible deniability if you ever get audited - you may in fact still have a deduction not allowed by the IRS, but as long as you did it in good faith, you shouldn't be liable for any criminal offense.
This is my US-based accountant for my US-based corporation, but I'm sure it translates well.