US commentators on the 79th Academy Awards spent many column inches noting the international flavour of this year's event. And indeed there were a remarkable number of nominations in the main sections for Mexican film and film-makers.

The strong presence again of the British - particularly Helen Mirren's regal procession to her shoo-in best actress honour - may also have given the impression of a foreign invasion.

The sense of the Oscars under siege was followed by a sense of relief that the final big winner was a great US director, Martin Scorsese, whose The Departed saw off Babel and The Queen. But it seems remiss not to recall that The Departed was produced by a Brit, Graham King, and was a remake of a Hong Kong movie.

And, of course, Scorsese has always been a director with a true global vision, indeed the champion of film-makers neglected in their home territories, such as Michael Powell.

This year's commentaries in the US media are perhaps a reflection of a rather belated understanding that the studios have turned their attention from a strong but saturated home market towards further fields.

But the notion that this is a case of a grand US institution getting dragged into a globalised market is ahistorical. The focus of Hollywood may have been firmly trained on a buoyant domestic market for many years but the net for talent has always been wider.

The Oscars were established by the studios (founded themselves, lest we forget, by European immigrants) as a means of promoting film to the world.

More than half of the 13 winners at the first awards ceremony back in 1929 were born outside the US: director of best production winner Sunrise, FW Murnau (Germany); best actor Emil Jannings (Switzerland); best comedy director Lewis Milestone (Russia); best writer Benjamin Glazer (UK); best cinematographer Charles Rosher (UK); and special award winners Charles Chaplin (UK) and Warner Bros (founded by Polish Jews).

Of course, the US at the beginning of the last century was still being formed by huge waves of immigration. There is a strong argument that it was Hollywood films that created many of the great national mythologies around which the nation was united.

This year's ceremony is worthy of as much note for the fact there are so many nominations for those Americans from origins excluded from recognition for decades, particularly African Americans (The New York Times notes this week that if there remains a colour bar, it is in international territories, not at home).

The discussion point this year should not be the wealth of international talent, which has always been there, but the distribution of films outside their countries of origin.

The number of foreign films shown in the US is still tiny and where it happens the films are often channelled into an arthouse niche that may attract awards but find it difficult to establish roots among customers.

European commentators like to see this as a sign of US isolationism, even philistinism, but it is little different in Europe where films from one territory rarely travel even to its neighbours.

Diversity in nomination lists means little if it does not lead to diversity at the box office, or wherever customers choose to see films. That challenge is already well recognised because the studios for some time have understood the commercial potential of a global market.

If one wanted to read an international trend from the Academy Awards, it is not about invasion by foreigners but about the great global medium of film realising its true worldwide potential.

Oscar may reside in California but he has always belonged to the world.