I understand the number of witnesses is not growing much, or is actually decreasing, in a few originally important countries. I also understand that growth in the United States come from non-white and possibly non-American congregations, and that the WTBTS' growth, as a whole, comes from developing countries (Latin America, maybe Africa). I notice that the training school for missionaries, Gilead, is in the United States. And I read somewhere that the society sort of prefers American missionaries because they have been trained under the society's more direct control. Witnesses who speak English can more easily read the original Watchtower documents and have easier access to them. Should the number of American witneses not grow, would the WTBTS survive?
I'm sure that the branch offices in developing countries don't usually contribute with much. Mexico and Brazil, given their large size and relative situation, might be important contributors. But I don't think the Malawi witnesses contribute with much.
What do you people think?