Resetting the country on Primary Address

Hi,

In order to resolve some compliance issues, we need to blank out the PrimaryBillToCountry if the user doesn't specify any Address details.

I set up a workflow with the trigger when a new record is saved

IfNull('<PrimaryBillToStreetAddress>',"Y")="Y" AND IfNull('<PrimaryBillToCity>',"Y")="Y"

and then to update the Country field as

[<PrimaryBillToCountry>]=""

if I create a new account record, and don't specify address or city, the country value still stays as USA.  Am I doing something wrong here?

Thanks,
Jo-Ann