From what Osensei has told students, the Okinawan people had great difficulty during these times between the destruction of their island and food shortages (Master Kyan died as a result of a food shortage).
Many Okinawans aided the Americans because as Sensei Hayes said, "They knew that the Americans had to be there if the Japanese were going to ever leave." Osensei was one of these Okinawans. He was given the responsibility to bring much needed food and supplies to the Okinawan people.
Despite the length and brutality of the battle, the Okinawan people have maintained good relations with the Americans, in particular the military ever since. In fact, that is the main way that Karate made its way to America. Various masters, including Osensei taught karate to US Marines when they were stationed on Okinawa (especially during the Vietnam War) and these first American students brought what they learned back to their homes after the war and opened up the first American dojos, passing on what they'd learned.