Their push to take over places such as Burma was a major culture clash. The result was plain resentment. There was much resentment shown from the Burmese towards the British. Here they were completely powerless and controlled by a country that was located nowhere near their own homes--but thousands of miles away. British officers walked around with their guns to keep the appearance of control, and Orwell was the object of much of that resentment.
The Burmese lived a life of hard labor and had no use for technology. They were a pre-industrial civilization. England was so much further along than that, so the clash was very obvious to both sides of the issue.