Thanks Matt R for the correction. That's what I get for relying on memory.
Regarding the Blood Debt, in Peter Hart's The Somme: Darkest Hour on the Western Front, he states "even if (British General) Haig had fully realized the depth and breadth of the losses suffered by his assaulting divisions on 1 July he could not have aborted the offensive without seriously jeopardizing the entente cordial with France and Russia...They were unlikely to look on with any great sympathy if Britain tried to evade her share of 'the butcher's bill'."
After France's mauling at Verdun, and according to General Haig, French Commander Joffre expressed the view that the French Army was demoralized and near collapse. Haig and the British command had favored an August 15th attack, allowing for build up of allied forces and artillery reduction of the German defenses, but Joffre was of the opinion that the attack must launch no later than July 1, saying "the French Army would cease to exist if we did nothing until then."
If you question Hart's credentials, he is none other than chief historian at England's Imperial War Museum in London, the government museum for World War 1.
As for it all being quite mad, on that we can agree.