First I am not a tax expert or qualified to give tax advice....
With that out the way, I am in Australia and my understanding is that when I ship goods to Amazon in the US for sale on Amazon.com that is an export sale so no sales tax (GST) is due here. I am still taxed on profits I make of course, but I presume you are talking sales tax.
When Amazon finally gets to Australia and I am shipping goods to a warehouse here in Australia then my presumption is that would be a domestic sale and subject to sales tax.
The sale is taking place in the country where the amazon warehouse you shipped too is located.
So if the warehouse you are sending to is in another country from where you reside/have a business/ are resident for tax purposes then you would not be accounting for sales tax in your country. If the warehouse is in your country, then sales tax is going to have to be accounted for by you.