My Citibank card has almost never failed me, except in the airports in Belo Horizonte, Brazil and Georgetown, Guyana, where there were no machines that would accept it. I travel almost exclusively in emerging-market countries (a.k.a. high risk). It is true that Citibank is familiar with my travel patterns and doesn't blink when I put my card in an ATM in Uganda, for example, but the fact that they are present in so many countries is a big help.