What he is referring to is that if one is a citizen of the US, one
must get a US license to operate where the US has jurisdiction
regardless of what multiple citizenship or other licenses one holds.

As a UK citizen, I can use my Australian license in the UK so long as I am
visiting for less than 3 months. After that time, the privilege expires and
I have to get a UK license. Much the same as driving licenses.

Doesn't the US do the same?

--
Jack VK2CJC / MM0AXL
FISTS# 9666
Mid North Coast Amateur Radio Group
http://www.qsl.net/mm0axl/mncarg/index.html