International Drivers License
In the past, the research I've done in this direction indicated that insurance could be obtained as long as a person had obtained an international drivers license. Unless something has changed, this is probably still the case at least with some companies. My advice is shop around with some other sources, and see if some other company will insure with the international license alone.
(Run a search on the forum using "international driver license" and you'll come up with the information I've posted on this in the past, for what it is worth.)
Bob