To explain the reason for this American infiltration of its apparently otherwise solely Cornish collection, the Tate has produced a few explanatory plaques and the aforementioned catalogue. The result is a polite nod at an emotive subject and, in effect, an embarrassing admission of a connection that cannot be ignored but that - one has the impression - is thought better left well alone.
For over 20 years, the St Ives artist Patrick Heron has been banging away on the subject of "Who did it first?" Did the Americans or the St Ives artists "invent" and refine the form of abstract expressionism prevalent in the late 1950s? Did Morris Louis produce horizontal stripe paintings before Heron, or vice versa? Was Peter Lanyon influenced by De Kooning, or vice versa? How does William Scott relate to Robert Motherwell? Heron has produced detailed evidence to support his pro-Cornish theories and this is not the place to support or counter these in detail, save to say that they do give good pause for thought. Surely, though, the Tate St Ives is the very place for such a confrontation - the evidence of our eyes being the most persuasive argument. And, if their curators were so intent on making the connection, then why not do it in a way that was genuinely provocative rather than via this half-baked excuse for an exhibition?
It is hardly as if the works are unavailable. A relevant painting by Kline already hangs, isolated and unconnecting, in the gallery's atrium. Rather, the reason is that the American question is just too controversial and exciting a subject for a gallery increasingly characterised by its evasiveness and diffidence - a gallery that would rather devote half of its space to children's art workshops (an admirable impetus, but surely in moderation).
There is nothing in the Rothko display or the catalogue that dares to challenge the received orthodoxy that modern abstract art was made in America. Rothko is repeatedly referred to as "the visiting dignitary" - "a great man" - and we are asked to marvel at how this messiah could actually exhibit human tendencies. "He is remembered to have enjoyed himself dancing" [No!] ... "and finally, helping with the washing up" [Gasp!]. The visit, we are told, served "to validate the town's importance as an artistic centre and to assuage any anxieties of provincialism". But the very fact of these words confirms the abiding impression of St Ives as having just such a character - an impression created largely by the cultural imperialism of the American critic Clement Greenberg and supported, albeit unwittingly, via the acceptance of the laurels handed to Rothko and his fellow abstract expressionists by not only Lanyon, Heron, Scott and the St Ives painters, but by such French tachistes as Georges Mathieu. For lyrical abstraction in the late 1950s was a universal phenomenon, only claimed by the American critics as their own in a blatant attempt to parallel their undoubted post-war industrial world domination with a similar cultural supremacy. The art produced by the major British West Country artists during the 1950s - Lanyon, Barns-Graham, Heron, Frost, Scott and Davie - was in its own way quite as important as that coming out of New York. Certainly the British were excited by transatlantic rigour and scale - but the Americans have since also admitted to a fascination with aspects of the work of their Cornish counterparts.
Rothko's visit was not a messianic blessing - rather, it was a meeting of parallel minds excited by the exchange of ideas. Certainly, the catalogue pays lip service to the debate over Greenberg's importance as a national polemicist. But it brushes off any serious discussion with the glib conclusion: "The dominance of American art seems to have been assured regardless of its political manipulation ... by the time American artists exhibited in Britain, their reputations there were already well established." What it fails to mention is the cross-fertilisation of ideas that resulted at the same time from British artists exhibiting in New York. Between 1956 and 1965, Lanyon, Scott, Davie and Heron had no less than 14 one- man shows in New York. Were the Americans above such influences? Certainly they were, says Greenberg, but to take this view today is laughably misguided - although, doubtless when this article appears, I too shall be labelled by some as xenophobic, a crank, as was Heron himself.
In truth, Rothko's visit to St Ives, at the invitation of Peter Lanyon, has been amplified into undue significance. It came at the end of a European holiday and revolved around social occasions - an evening drink with Lanyon at The Tinners Arms, a party, drinks with Heron, lunch with Frost and Paul Feiler. It lasted less than three days. It was a footnote in the history of St Ives abstraction. It was also a huge blunder on the part of British artists. Without realising it, the artists of St Ives - in particular Lanyon - had provided the crusading evangelists of American art with a useful source of ammunition. This exhibition merely perpetuates an abiding cultural misconception whose demythologising remains overdue.
n 'Mark Rothko in Cornwall' runs to 3 November at the Tate Gallery St Ives (01736 796226)