The U.S. Navy never had P-3s in Korea or Japan. At the height of the Cold War all Pacific Fleet P-3s were stationed at Moffitt Field in California and Barber's Point in Hawaii. They deployed to Adak and Midway.
Recently they've deployed P-8s to Okinawa. I have no idea whether that's a permanent plan or not.
In the control towers at Kunsan and Osan, I had more P-3s land and take off than I care to count, between the 5 short tours I ‘ve had from 1985 thru 1996.