"Who on earth is this person?"
The feller who has persistently defended sales of chemicals to Syria, has described suggestions that military intervention as "gung-ho", or "leftie", or "miltarism"... (presumably including Obama, Cameron, Hague et al in this description), has insisted that the chemicals licensed for sale to Assad were "harmless" and having been shown otherwise, has moved on to another thread to make the same claims, has suggested that is is prejudiced to single out Britain because "everybody else was doing it", has proposed that Assad should be provided with "riot control gear" and has supported his being sold armoured cars and water cannon.
On identifying past British sales of small arms ammunition as "sniper bullets" at the time Assad's thugs were cutting down women and children in the street, possibly with these "sniper bullets" he then entered into six conflicting explanations why they were not "sniper bullets, finally settling on "I thought we were talking about Libya".
On a currently running thread he has all but driven the subject into the ground with his long-running and deliberately obstructive claim that the Irish famine was "nuffin' to do with Britain".
Whenever the name "Israel" is mentioned he has entered into a long defence of the mass slaughter of refugees, chemical warfare, illegal land seizure, attempts at mass starvation, the killing of innocent civilians, the forcible moving of nomadic communities onto toxic land......
Irish violently sectarian marches he has described as "fun" and has attributed the long running violence caused by those marches as down to "bored children".
In the past, his causes have included the description of violently Antisemitic poetry written and distributed by members of the upper classes at the time Hitler was embarking on the annihilation of six million Jews as "harmless".         
He first came to public notice with his suggestion that immigrants with aids should not be entitled to medical attention......
The list goes on and on.
A reoccurring symptom of this disorder seems to be either outright denial (as is about to happen again) despite the fact that all this is archived), or an urge to blame somebody else – a malignantly evil force driving him to do it.
Now call me picky, but I suggest that this is somewhat over-the-top extremism verging on obsession.
I'm sure that the lovely Detective Sergeant Beckett would have detected a pattern to all this and I have no doubt that the psychiatric profession has a name for it.
Jim Carroll