My father who died last year was a slave for three and a half years, as prisoner of war in Malaya, and worked building the Burma railway.
He was beaten and starved and weighed only five and a half stone at the wars end.
He and his comrades never got an apology from the Japanese government, or any compensation.
Blairs government gave them all �10,000 each in 1998, (what was left of them).
I think an apology would have helped, when he was alive, but it would be worthless now. Same with the slave trade, there's nobody directly involved to apologise to.