From time to time you have to say, or rather, are compelled to tell a hard truth that will hurt someone for their own betterment. I refer to this as "ruthless compassion".
ruthless
Function:adjective
Date:14th century
: having no pity : merciless, cruel {a ruthless tyrant}
— ruth·less·ly adverb
— ruth·less·ness noun
compassion
Function:noun
Date:14th century
: sympathetic consciousness of others' distress together with a desire to alleviate it
— com·pas·sion·less