It depends on which tribe it was, some were friendly, some were not
The supporters of the use of the atomic bomb rejected the idea of dropping one on a deserted island because they did not want to waste one of the remaining bombs.
Even though the use of one of the atomic bombs on an uninhabited location was considered, it was turned down because of practical reasons. There were only two bombs available in August, 1945 and they worried that the demonstration bomb might turn out to be a dud.
They could not learn how to read or write it was seen as a privilege only a powerful white man should know.
It was replaced by the Russian tricolor
Increase of crops due to new innovations with the farming technique is one that comes to mind, not very sure about other factors though, sorry