Is my pin oak dying or just stressed?

Chlorosis comes first: interveinal yellowing on the newest leaves at the branch tips while the veins stay green, worsening each year until leaves go nearly white with scorched margins and twigs die back. The differential worth knowing is bacterial leaf scorch — it browns the leaf margins with a yellow band between dead and green tissue, hits a few limbs at a time and returns worse annually, and unlike pH-driven chlorosis it has no cure, so trees run 5-8 years to mortality.