SINCE well before the last century began, Bolivia has fought repeatedly with its neighbors over the riches on and under its soil.

So far, it has lost every time.

Once more than three times the size of Texas, half of the land Bolivia once held is now gone, along with a long Pacific coastline and, some have said, the country's dignity.

Even lowly Paraguay, also landlocked and impoverished, took its share — in a three-year war that ended in 1935, when Bolivia had the edge in manpower and equipment, and a German World War I veteran, Gen. Hans Kundt, to lead its forces.

That history of humiliation was very much on Bolivians' minds last week when their president nationalized the country's natural gas fields, and in doing so picked a fight with the giant next door, Brazil.

President Evo Morales, a leftist who campaigned for election last year on promises of restoring national pride, clearly hopes this move will prove a brilliant gamble, but others say it could bring Bolivia economic ruin.