Several claims he makes struck me as dubious. Firstly he repeats the old myth about Churchill and the use of gas against the Kurds:
In 1920, as Secretary for War and Air, Churchill, enraged by Iraqi resistance to British colonial rule, declaimed, "I am strongly in favor of using poison gas against uncivilized tribes to spread a lively terror."
Eighty years later, Saddam Hussein and Chemical Ali would be hanged in Baghdad for doing what Churchill urged Britain to do and what Britain did.
Churchill specifically referred to the use of tear gas to minimise fatalities which is not remotely the same as Saddam and Chemical Ali using deadly nerve agents to create mass casualties and induce panic. Incidentally Chemical Ali has not been hanged at the time of writing.He also makes Churchill bear the principle responsibility for events where he was at best a bit part player- for example he excoriates Churchill for the Washington Naval Conference, where fixed ratios were established between the naval power of Great Britain, the USA and Japan. Churchill also criticises the effects of this treaty in The Gathering Storm, but at the time of the conference he as not the First Lord of the Admiralty, not the Prime Minister & not the Foreign Secretary, yet in Pitchfork Pat's eyes Churchill seems to bear the primary responsibility.
The bombing of Dresden which is depicted as an assault on an unimportant city of a defeated power, is described as causing fatalities numbering from "from 35,000 to 250,000". Yet the only historians who have concluded such preposterously high figures numbering over 100,000 are the likes of David Irving and other pro-Nazi partisans.
Buchanan's criticisms of Churchill are all over the place as he swings wildly from condemning him for seeking war (with Germany) but also condemns him where he tried to avoid war (with Japan and with the USSR for example).