I'm reading a collection of George Orwell's journalism, mainly from the tail end of World War Two. The collection (The Observer Years) includes both his op-eds and his travel journalism. From my point of view, the travel journalism is far, far better: it's rich, finely detailed and full of surprising details about the way people actually live. It does a better job than anything I've ever read at depicting life in France and Germany in the post-war period. He has, for example, a wonderful description of Paris just after liberation: the people are impoverished and hungry, there's a strong nationalistic sentiment in the air, and at the same time women are wearing outrageous hats, and there are long lines in front of every movie theater. I mean, details like that make the scene seem real.
The op-eds -- the opinion pieces written for, and about, Britain -- are far less interesting. There are far fewer details of daily life, and far more cliches; he relies on many more generalizations about what "ordinary" Britons feel and he rattles off a lot of canned phrases. I'd never realized how conservative Orwell was. British imperialism, the colonial system, are things he accepts as inevitable. He's willing to criticize the way that the system is implemented, but not its basic tenets.
So I suppose doing international journalism was easier for him because he was able to shake off his own prejudices and describe whatever scene was in front of him. While when describing Britain, he can't really seem to let go of the Old Etonian point of view.