They use events from the past as weapons in their own nation's battles. While a historian tries to collect all the relevant facts and put them together as a coherent picture, the nationalist selects those pieces of history that fit his purpose' ignoring the others. Like other men and women, historians have political goals and ideologies, but a true historian acknowledges his errors when the facts do not support his belief. The nationalist apologist never does so. If the facts do not fit his theories the nationalist ignores those facts and looks for other ways to make his case.
True historians can make intellectual mistakes.
Nationalist apologists commit intellectual crimes. The Armenian issue has long been plagued with nationalist studies. This has led to an inconsistent history that ignores the time-tested principles of historical research. Yet when the histories of Turks and Armenians are approached with the normal tools of history a logical and consistent account results. Historians first ask the most basic question.