It’s a distinction of enormous difference.
The entire raison d’etre of International Socialism is to get “the workers of the world” to unite and overthrow the capitalist system, ushering in a world of peace and plenty for all. The survivors, that is.
OTOH, the purpose of National Socialism is to band the Nation together to dominate over other nations. In the Nazi variety adding idiotic and unscientific racial theories to their ideology.
The Nazis made no particular attempt to force satellite states to adopt Nazi or fascist systems. They just didn’t care about such things, as long as their satellites were subservient.
Ambitious men in those states generally pushed for them, on the not unreasonable view at the time that fascism was the wave of the future.
“Workers of all lands, unite to smash the rule of English capitalism! You young upward-striving nations of the earth, combine to annihilate the old English dragon who blocks the treasures of the earth and withholds from you the riches of the world.” - Robert Ley, Head of the German Labor Front