Reading between the lines, it seems that the actual history is the following:
(1) When Japan surrendered, the Japanese government feared that the conquering Americans would behave exactly as the conquering Japanese did in the Philippines and elsewhere: i.e. round up whatever women they thought were attractive and put them in camps for systematic rape.
(2) To prevent this, the Japanese government hit upon the idea of ordering local women who were already working as prostitutes to report to police barracks.
(3) The Japanese government then welcomed US troops to these makeshift brothels to enjoy free sex at Japanese government expense.
(4) The Japanese government paid these women, and apparently paid them much better wages than non-prostitutes were making.
(5) Some of these prostitutes complained that they did not want to sleep with American soldiers, but preferred Japanese. So the government paid them more to convince them to go through with it.
(6) When Douglas MacArthur became aware of the arrangement, he decided to abolish it a few months after it began.
Not a glorious moment in US history, but it is understandable that not all GIs would turn down an offer of free sex, especially when it was advertised as a government-sponsored service by the local police.
There is no comparison between this and the systematic rape Japan practiced in conquered territories - but the AP is attempting to compare it.
AP stinks and I KNOW why they are raising this issue right at this point - to discredit American military forces in Iraq.