In which, if any, countries is truth not an absolute defense against a libel charge?

in English law, if sued (not prosecuted) for libel, the respondant has to prove that his statements were true. It’s not up to the plaintiff to prove that they weren’t.
Alternatively, if it’s not susceptable of proof, that it was ‘fair comment on a matter of public interest’. In recent years the ‘Albert Reynolds defence’ (named after a former Irish premier who sued in the English courts) has emerged from the courts; that even if the statement was false, the question was of such importance to the public that it deserved to be aired. Several papers that have run an ‘Albert Reynolds’ have subsequently lost, however, notably the London Daily Telegraph vs. George Galloway, MP

Pretty much. OTOH, they have a field day maligning overseas individuals and entities.

There is a way to out an outfit that’s doing bad stuff but it’s time consuming and, if you wish to take it to court, extremely expensive. To blacklist my former employer on one of the English teachers’ websites here, I had to stick to a report of events and the site’s Korean lawyer scrutinised the report very carefully. (E-mail me if you’d like to see the report; my e-mail’s in my profile.)

It used to be that if you pleaded truth as a defence, and lost, then the plaintiff was entitled to aggravated damages.