His intentions for the Theravada Buddhist community (or at least the Sinhala component of it) were certainly good, but the effects his philosophy brought about devastated the small island nation. In any event, it is difficult to find a figure in Theravada Buddhism, short of Buddha himself, who had a greater impact on how doctrines were interpreted in Sri Lanka. As a result of Dharmapala, the concepts like dana and doctrines like the first precept were drastically changed. Upon viewing the carnage of the Sri Lankan Sinhala-Tamil conflicts, it is difficult to say Dharmapala was benign. But, upon viewing his vision for Buddhism, it is also difficult to say he was hostile. What is not difficult to determine is his tremendous impact on Sri Lankan Buddhism in both the monastic and lay communities.
A hundred years after the life of Buddha, the Second Council was held. At this council, several minor disciplinary rules were clarified. For instance, it was a cause of controversy if monks should be able to accept gold and silver as alms. Several doctrinal concepts also arose at this council. There was a group of monks who argued that there was a way to become even more enlightened than an Arhat. They claimed that a person could achieve actual Buddhahood. This major doctrinal question was deliberated over by a council of elders. It was eventually determined that the concept of achieving Buddhahood was not in the Buddha’s teachings, and that it was blasphemous against the religion. The monks, however, could not accept this and formed the now-popular Mahayana tradition. The Second Council was an internal, benign force that ended up fracturing the Buddhist community in two. It served to clean up the doctrine, however. Because of the Second Council, it became set in stone that the highest possible level of enlightenment one can obtain in the Theravada tradition is that of Arhat.
This discussion has observed three external forces: British colonialism (especially the Kandyan convention), Portuguese colonialism, and Dutch colonialism in Sri Lanka. One force—Asoka—was difficult to categorize. There were also three internal forces: the Thudong monks, Dharmapala, and the Second Council. Of these seven forces, four were benign: British colonialism, the Thudong monks, the Second Council, and Asoka. Two were hostile: Portuguese and Dutch colonialism in Sri Lanka. One force—Dharmapala—was difficult to categorize. Some forces had a stronger effect on the monastic community than the lay community, while others affected the lay community much more drastically. Not all of these forces caused a doctrinal change in Buddhist tradition. These were only a handful of the forces that shaped modern-day Theravada Buddhism—countless other forces contributed to the formation of modern-day Buddhist soteriology.
This discussion has also looked at a few doctrines affected by these forces, such as the Noble Eightfold Path and the Five Precepts. It appears from the examples that internal forces more easily change doctrinal Buddhism, as external forces both benign and hostile did not cause drastic change in doctrinal Buddhism. 