Una discusses the Spice Islands in this Staff Report: Why are there so many spices in the Spice Islands?
After reading this, I wonder, why are there so few sources of nutmeg and cloves? Nutmeg only seems to be grown in Indonesia and Grenada. Cloves only from Indonesia and Madagasca. If they are so valuable, you’d think that other tropical islands would try to cultivate them. So why don’t places like Hawaii or American Samoa grow some and reduce our dependence on foreign-grown spices?
That’s a difficult question to answer authoritatively. I did come across several notes along the lines of “nutmeg trees were planted there but the climate was not amenable” and “clove trees are very finicky about their climate”, but I was really having a hard time finding “clove trees need x amount of sunlight and Y amount of rain at A and B temperature ranges”. Fungal and insectal parasites/attacks might also be an issue. My researched guess is that the trees are just very sensitive to the particular temperature extremes and sunlight available, rain, soil acidity, and other conditions found in the places where they are commercially grown.
There have been economic drivers to try transplants throughout history, certainly, and from an early time. Especially when there was a monopoly involved (my the Dutch or someone else). IIRC there were more than a few efforts in ages past to grow peppercorns and even nutmegs as far north as England, with very poor results, but I’d need to verify the source on that.
I heartily recommend Nathaniel’s Nutmeg as a further source on this topic.
Why does any country buy anything from any other? Because it’s cheaper to buy them from established cheap efficient producers than grow them yourselves.