Fifth freedom rights are also known as beyond rights. This means fifth-freedom routes have to originate or terminate in one's own country. So, an airline can offer no more fifth freedom flights than the number of flights it has to the US. Furthermore, even though the US allows fifth-freedom rights for airlines from the nations that have open skies agreement with the US, fifth-freedom rights by definition involve a thrid country. There are many countries who might not grant traffic rights to and from the US for foreign airlines.