From my very limited understanding, Art Deco was, if not originally American, then it flourished most significantly in the USA, and to some extent in the UK, and it looks extremely
capitalist. It's about opulence and luxury, and is very much a design by the elite, for the elite. Even in buildings that were used by ordinary people, like theatres and cinemas, it gives the impression of wanting to make you think you're in a hotel in Manhattan or LA. It makes you think of Bertie Wooster in his top hat and coat-tails, and flappers in shimmery golden dresses, drinking champagne. It's associated with the first great flowering of Hollywood, with aviation when it was strictly a luxury for the very rich, and with the jazz age - but jazz very much in the sense of a band of black musicians in tuxedos playing at a soiree in a hotel ballroom organised by some moneybags industrialist, not jazz as it actually evolved, as music that black people danced to in clubs in Harlem.
This is probably better summed up in the very name of this building than by anything I could write:
Whereas international modernism was associated with the Bauhaus school (as Rudewhy points out), which had an ideology that was, if not Marxist exactly, then at least socialist-leaning and very much geared towards mass-produced objects that ordinary people could afford, and buildings that were public and municipal, and not just these great phallic monuments to personal success. So it had more currency in the USSR and in parts of central and eastern Europe that had left-wing governments or at least widespread leftist movements than it did in America or Britain.
So you had Malevich designing buildings that would have looked like this, for example:
At least, that was the case in the 20s. After Stalin assumed the dictatorship, international modernism was deemed a bit too international (i.e. possibly capitalist and/or Jewish) and the USSR swung into a more culturally conservative phase, following that brief early period of radicalism and relative artistic freedom.
And then not long after that, the movement also ended in Germany, for obvious reasons.