This seems sublime. Japan has never had a legitimate claim to Guam to my knowledge. Spain ceded Guam to the US following their defeat in the Span-Am War in 1896 or so. The US maintains a major Air Force Base (Andersen) and a naval facility on Guam; furthermore, if you check your Form 1040 instruction booklet, you will see that Guam is a US taxation district! That's because Guam is a US Territory! Much like Am Samoa and USVI. Don't believe everything you read or hear.