Do country have any significance in credit card transaction - paypal

Question

I went into the developer portal and created a test account for a non US account. Transaction with this credit card number with the C# code below works fine.
But, my question is whatever the country code is provided, paypal soap api allow me to do the transaction without out any problem. Is this a correct behavior or there is some setting that can enforce the API to validate the country.
//address of the card owner
var cardOwnerAddress = new AddressType
{
Street1 = request.BuyerAddress1,
Street2 = request.BuyerAddress2,
CityName = request.BuyerCity,
StateOrProvince = request.BuyerState,
PostalCode = request.BuyerZipCode,
CountryName = "USA",
Country = CountryCodeType.US, // country code
CountrySpecified = true
};
//card owner object
var cardOwner = new PayerInfoType
{
Payer = "",
PayerID = "",
PayerStatus = PayPalUserStatusCodeType.unverified,
PayerCountry = cardOwnerAddress.Country, // country code
Address = cardOwnerAddress,
PayerName = cardOwnerPayerName
};

Answer 1

Typically, with AVS - Address Verification System(s), and also CVV2 the most done is checking the street number and numbers from the postal/zip code (numbers because they are constant, where people can type "st.", "street", "st" etc for their address. Thus the country really doesn't matter.
Names, for some cards, can be checked too, though as you can imagine, this can be a pain with people not typing their name exactly as it appears.
You can also, with PayPal, set filters in your account to specify which countries you will accept payment for - though this has nothing to do with verification, it's just PayPals layer on top.
Paypal list out what verification you can set up here
https://developer.paypal.com/docs/classic/api/AVSResponseCodes/
And a little information on AVS can be found here https://en.wikipedia.org/wiki/Address_Verification_System