The body of Christ does not rely SOLEY on Westerners to do the work of missions. But it would certainly seem amiss if the country which publishes the most Gospel materials and commentaries and hosts the most seminaries would lag behind the rest of the world. Brazil and Korea are also big missions-senders as well. If you are concerned about the doctrinal integrity of those missionaries being sent, the solution would not be to leave the task to Third World pastors, but to make greater efforts to send doctrinally sound missionaries ourselves. All the world is not equally the mission field. There are places where the Gospel will not just naturally flow into by means of movement and immigration or travel. Some places need intentional strategizing and deployment of resources to reach. In my experience, most missionaries do not act as if NOTHING is being done - but we do act as if NOT ENOUGH is being done.