He's not really a historian, though he was trained as one and wrote a solid history of Germany's foreign policy as regards Europe - east and west - "In Europe's Name".  His true talent is in writing long essays on current events (much better than his Guardian columns). That's what his book on Solidarity really is, and you can't find a better description of the atmosphere of the Polish and Czech anti-communist opposition than in his essays collected in "Uses of Adversity"