Yes I watched a documentry on this.
The Japanese invaded the islands. Actually these were the first American lands to be invaded since the last time(American Mexican war?).
Anyhow they were unopposed of course. Later on when the US troops were island hopping in the Pacific, they sent a force to these islands.
The Americans invaded, and the Japanese used the same tactics they used in the Pacific. They let the US troops land on the island unopposed, and when they started moving in, the Japanese attacked.
They were finally all wiped out, since none of the Japanese troops surrendered. Actually one GI of the time said that when they finished their ammo, they attacked one last time with bayonets.
He was talking about how his view of war and of the Japanese changed that day. He said he killed about 5 when they attacked with bayonets. After the "slaughter" he went through one of the dead soilders pockets, and found a diary and a picture of a woman and a baby.
The program also showed him going to Japan to give that diary and picture to the widow. The diary revealed the man was a Japanese doctor, educated in US. In the first days he writes about how harsh it is here and how much he misses his family. He writes about how he thinks this war is crazy and going out of hand. Later on he writes about how the US troops came to the island, and there is no hope of evacuation, reinforcements or supplies. He talks about other soilders he cannot help because there are no medicine available. Slowly he writes more and more about how he is willing to die for the emperor.
The final entry into the diary is a farewell to his wife. He says he loves them. He says they are out of ammunition. He says that they have decided to attack with bayonets, and those who cannot stand will be given grenades, to blow themsleves with the enemy. He then says he will die with honor and then 'long live the Emperor!'.
The American man was crying all the way. He says that when he read the translation he understood how similar this doctor was to him. He felt guilty all these years and said he felt closure when he handed the diary to the family of the doctor.
It was a really interesting and moving documentry...