Uh, in WWI we were not fighting Japan.
Anyways, the cross does not have to associated with religion or in particular Christianity. The Romans used the cross as a execution/torture device. Just because one man who some believe is divine was executed on a cross does not mean all crosses are in memorial to him. The person who complained about this cross needs to be more tolerant of others (as does the ACLU in this case). Since the cross is just a cross, no associated Christ figure (dead, dieing or otherwise), it can not be absolutely associated with Christianity (and therefore the ACLU needs to back down off their high horses). Also, since the structure is 75 years old, I wonder if it can get into the national historic registry, protecting it from destruction.