Makes no difference, of course, when the strategists are tired or stupid or distracted or whatever it is that undermines good judgement. I give you the Battle of Arnhem (1944). Operation Market Garden was conceived in a fearful rush - fighting in Normandy was still being conducted in the last week of August, and yet the Netherlands, two whole countries further on, was being invaded from the air by 17th September. Actually, the plans were based broadly on several previous airborne ventures that were never launched, so they didn't start entirely from scratch. However, any plan needs to be crafted specifically for the precise circumstances at hand.
And by Heaven they screwed up. Many will be familiar with the episode in detail, and here's not the place to retell the whole story. However, one massively salient (no pun intended) feature was that no account was taken of how the Germans might respond. The enemy was deemed to be a passive entity to be taken by surprise, brushed aside and more or less left in the role of a lamely protesting spectator.
But the German army was never quite like that: its powers of recovery, reorganisation and tactical response were astonishing, legendary. They'd been doing it to the Allies all up Italy and across the Eastern front for a year or more. And of course at Arnhem too: they responded, adroitly, resolutely and successfully.
I bring all this up because it's been highly relevant all through the Brexit fiasco, and continues to be so even at the death. Every player - May, ERG, Official Labour, Starmer's private operation, any number of backbench cunning-planners - they all announce something that cannot be delivered unilaterally; that necessarily involves the enemy. And Selmayr is quite capable of reacting, in his own interests, to whatever comes his way. Parliament can pass all the motions it likes about renegotiating the deal, removing the backstop, delaying the Big Day, etc etc. But it makes no odds if the other side has different ideas. Even (as I understand it) 'unilaterally' revoking Art 50 is a qualified matter: it may not restore the status quo ante, and might come with bells and whistles (e.g. - can't invoke it again any time soon; must be 'genuine' etc). And even that's only an Opinion: yet again, the enemy may have a surprise for us if we try it.
Hence I reply to 'Andrew' who noted BTL the other day a snippet from Alphaville:
"...a theoretical non-payment of pre-committed EU funds by the UK would lead to an immediate funding gap for Commission programmes. Borrowing is not an option for the EU due to the terms of the Treaty on the Functioning of the European Union. An emergency budget renegotiation meanwhile is possible but extremely politically complex, and unlikely to offer an immediate solution""So much for weak negotiating position", said Andrew: but I fear that's to fall into the trap again. Suppose May assumes that's a knock-dead gambit on our part and pulls the plug on the first payment of the £39bn (due quite soon). We know exactly what would happen. We'd wake up next morning to find a headline stating that actions had been taken overnight under some emergency power that Selmayr had invented for himself, and that the Commission was content to pursue the UK through the international courts at its leisure.
A comment I made ages ago on George 'Boy' Osborne (equally aposite to Frederick 'Boy' Browning) is that being by nature a strategist is all very well; but what is needed is good strategists. Do we have any? I've seen absolutely no sign of one.