I believe western influences did negatively impact Japanese cultures in Okinawa during U.S. rule, but given the circumstances I believe this can be justified. Furthermore, these cultures would have and continue to be negatively impacted as the people are exposed to other cultures from across the world. While it is unfortunate, it seems it was bound to happen rather it be from the United States or simple globalization.
The military does not want to admit it, but porn and alcohol are staples of the military environment. It is not necessarily abused, but it is always present. This was no different during the occupation of Okinawa. The prostitution trade increased as well, which may have been the beginning of the Japanese porn industry. These things may have been illegal in Okinawa, but that is what the black market is for. Perhaps it was the Occupation that revitalized the Yakuzas.
Western influences did not negatively impact Japanese culture of Okinawa during U.S. rule. If it did, you would see more of an western influence in Japan if that were the case. If you look at things, there is actually a ton of Japanese influence in current United States culture today.
While there is still a lot of resentment toward the United States because of what happened during World War Two, it is still an incredible place and the blending of west and each which took place there is nothing short of spectacular. The people there seem somehow more informed than other parts of the world.
Western influences did not negatively impact Japanese culture of Okinawa during U.S. rule. In fact, the Okinawan people are some of the most healthy and vibrant people on earth. They have very high nutrition guidelines, low levels of sickness, and lead very spiritual lives. There are no widespread remnants of negativity within these people.