Winston Churchill was born into a political family and he was always a political animal. First, though, he was a professional writer; he made his living with his pen long before he won an election.
Anyone who worked under him well understood that if they won an argument the victory might only be temporary. There was the verdict of history to consider and WSC would no doubt help write that history.
Jonathan Jordan points out a classic example of the editorial tensions inherent when a work is both memoir and history.
All through the spring and summer of 1944 Churchill and his top military chiefs were reluctant to commit to the Normandy landings and the Campaign in France.
They opposed weakening the Italian front to mount a second landing in the south of France (Operation DRAGOON). They saw opportunities to make opportunistic attacks in the Balkans and on islands in the Aegean. Churchill (but not his generals) dreamed of a war-winning drive up the Italian boot and into Austria.
By July 1944 the American’s were out of patience. As the largest partner in the western coalition, they brushed aside British objections and insisted that DRAGOON go forward as planned.
Churchill vented his frustration to his top military advisor in July 1944:
As Jordan notes in American Warlords, Churchill chose not to include the whole memo in his memoirs. He preferred not to declare the American leaders “one of the stupidest strategic teams ever seen.”
I am not going to give way about this for anybody. Alexander is to have his campaign. If the Americans try to withdraw the two divisions still left with him, I shall ask you to send the 52nd division from the United Kingdom to breach the gap. I hope you realise that an intense impression must be made upon the Americans that we have been ill-treated and are furious. Do not let any smoothings or smirchings cover up this fact. After a little, we shall get together again; but if we take everything lying down, there will be no end to what will be put upon us. The Arnold-King-Marshall combination is one of the stupidest strategic teams ever seen. They are good fellows and there is no need to tell them this.
Post-victory good feelings are one explanation. So is the need to avoid offense to a vital ally. But even Churchill had to recognize that the American's strategic sense looked pretty good after Germany and Japan were defeated years ahead of schedule.
Jordan makes an interesting point about the role language played in the Anglo-American tensions during the war. The British perspective:
The British, especially Churchill, saw strategy as less a matter of time-tables and production schedules and more of a question of seizing opportunities when they presented themselves.
They distrusted the American mindset. Fixated on northern France, the Americans viewed military strategy as an unalterable blueprint, and strategic agreements as binding contracts among lawyers. Marshall and King could not see the value in extemporizing in northern Italy or the Aegean -- extemporization that would aid OVERLORD while lopping off key morsels of the German empire.
To Americans, this search for opportunities made the British look slippery and unreliable, forever trying to back out of solemn agreements.
Samuel Eliot Morison addressed this point in Strategy and Compromise:
Britain and the US were two allies “divided by a common language” in large matters large and small. Jordan again:
The British Chiefs, especially Sir Alan Brooke, never could seem to understand why the Americans had to have commitments well in advance. They accused us of being rigid and inflexible, not realizing the terrific job of procurement, shipbuilding, troop training and supply necessary to place a million and a half troops in England, with armor, tanks and troop-lift, ready to invade the Continent
American strategists were not immune to shaping history through intentional omissions. From Masters and Commanders:
Thing necessary for operations, to the Americans, were 'requirements,' while in the British vernacular they were 'demands'. The word 'demands' had an imerious ring to the American ear, and when the British presented 'demands', it sounded like an edict from King George III to his colonists. Similarly, the British might suggest that the group 'table' a difficult matter -- meaning lay it on the table for discussion -- while to the Americans, to 'table' something meant to set it aside for the future.
In 1956 Marshall made a terrible admission to Pogue about the lack of proper intelligence before D-Day. 'Don't quote this' he told his biographer, but 'We didn't know we were going to hit such rough country... G-2 [military intelligence] let me down every time in everything. They never told me what i needed to know. They didn't tell me about the hedgerows, and it was not until later, after much bloodshed, that we were able to deal with them.' Later in the same interview, after Marshall had said, 'We had to pay in blood for our lack of knowledge,' he repeated: 'Don't print that.'... The admission that Marshall was not warned about the bocages the deep, thick, ancient Norman hedgerows that gave the German defenders such fine defensive cover-- is a serious one, and a significant failure of US Military Intelligence (G-2). Brooke knew all about them because he had retreated over precisely that ground to evacuate from Cherbourg in June 1940, but his warning were largely disregarded as yet another excuse for not invading.