When the Salisbury show opened in the Rhodesian capital last month with all the bands, fanfares and speeches which made this one of the country's ???ig events, it appeared to reflect the feeling that all was well within this isolated nation.

A visitor to the show might never guess that it was a beleaguered country, supposedly cut off from the rest of the world's trade by sanctions imposed by the United Nations after the white minority declared itself independent in 1965.

Indeed, the Salisbury show did reflect the fact of the matter. That, until now, sanctions have made little impact on rhodesia. In the show ground, ???re were numerous stands exhibiting imported cars, agricultural implements, ???tors and consumer goods. In Salisbury itself, department stores are full of luxury items imported from America, Switzerland, France and Japan.

The fact that sanctions have apparently failed to bite is due largely to Rhodesia's neighbours, South Africa and the Portuguese East African territory of Mozambique, both of whom have chosen to ignore the UN call for a trade embargo.

Many of Rhodesia's exports and imports go by rail to and from the Mozambique ports of Beira and Lourenco Marques, while many more come up by rail and air from South Africa.

But Rhodesia's outward affluence masks the existence of real problems, which are growing worse.

Although there are still plenty of foreign goods on show, they are becoming more scarce and more expensive. Rhodesia is finding increasing hostility towards its products on the outside world markets and suffers serious shortages of foreign currency to pay for the imports it needs. Furthermore, the convenient traffic to and from Mozambique's ports is likely to come to a halt when a black government takes over the territory in the middle of next year.

At the moment, this trade is affected more by the conditions of war inside Mozambique and numerous strikes in the ports than by any declared policy of denying Rhodesia their use. But this positive move is expected once Portugual finally pulls out.

Rhodesia -- already facing a 50 per cent deficit on external trade -- will then be forced to use its only outlet, through South Africa. And this doubles the cost of exports and imports.

For the moment, Rhodesians appear content. The Salisbury show reflects a certain confidence. It is still possible to buy almost anything in Rhodesia, provided the money and the patience are available.

Yet for all the outward signs of prosperity, the chances are that Rhodesians are going to have to pay a much higher price for their independence in the future.