Muslim countries historically have banned Christian missionaries. For instance, in Morocco, The JWs who live there preach only to people who are already of a Christian faith. Proseletyzing to Muslims is illegal. If a need-greater goes into Morocco, they are on their own. WT gives them no support. I even heard about one couple from the US who went into Morocco who used ficticious names and occupations to get to stay in the country.
Also, my opinion is that the JW religion has built up on the backs of the Christian missionaries of previous centuries. The missionaries, both Catholic and Protestant, went into all those countries in South and Central America and Africa, translated the Bible into their languages, converted the people to their brand of Christianity. Those missionaries lived and died there, doing the hard work all those years. The JWs went in post-1940 and found a fertile ground in those who were disaffected for some reason and that is why JWs have been successful. In other areas where the missionaries were not particularly successful (India, Pakistan, Muslim countries, China), the JWs have had little success.
