goober said:
Not sure why you think that was an obvious fact to those soldiers? The obvious is it wasn't obvious or they would have come out. Why do you believe it was obvious to them? Obviously it wasn't.
For some reason I just thought of Orson Wells "The War of the Worlds"...
Maybe this might explain why it was obvious:
"Onoda first saw a leaflet that claimed the war was over in October 1945. When another cell had killed a cow, they found a leaflet left behind by the islanders which read: "The war ended on August 15. Come down from the mountains!"2 But as they sat in the jungle, the leaflet just didn't seem to make sense, for another cell had just been fired upon a few days ago. If the war were over, why would they still be under attack? No, they decided, the leaflet must be a clever ruse by the Allied propagandists.
Again, the outside world tried to contact the survivors living on the island by dropping leaflets out of a Boeing B-17 near the end of 1945. Printed on these leaflets was the surrender order from General Yama****a of the Fourteenth Area Army. Having already hidden on the island for a year and with the only proof of the end of the war being this leaflet, Onoda and the others scrutinized every letter and every word on this piece of paper. One sentence in particular seemed suspicious, it said that those who surrendered would receive "hygienic succor" and be "hauled" to Japan. Again, they believed this must be an Allied hoax.
Leaflet after leaflet was dropped. Newspapers were left. Photographs and letters from relatives were dropped. Friends and relatives spoke out over loudspeakers."
...
On March 9, 1974, Suzuki and Taniguchi met Onoda at a preappointed place and Major Taniguchi read the orders that stated all combat activity was to be ceased. Onoda was shocked and, at first, disbelieving. It took some time for the news to sink in.
"We really lost the war! How could they have been so sloppy?
Suddenly everything went black. A storm raged inside me. I felt like a fool for having been so tense and cautious on the way here. Worse than that, what had I been doing for all these years?"
http://history1900s.about.com/od/worldwarii/a/soldiersurr.htm
An apt analogy, Issoisso.