Effectiveness vs efficiency - why the mission should come first

The relationship between effectiveness and efficiency has always been a rich source of disagreement. I think a helpful distinction is:

Effectiveness - doing the right thing
Efficiency - doing the thing right

A recent auditor's report has found that the Ministry of Defence has lost track of assets worth £6.3bn. It is nearly 200 years since the Duke of Wellington wrote the following message to the British Foreign Office in 1812:

Gentlemen,

Whilst marching from Portugal to a position which commands the approach to Madrid and the French forces, my officers have been diligently complying with your requests which have been sent by His Majesty’s ship from London to Lisbon and thence by dispatch to our headquarters.

We have enumerated our saddles, bridles, tents and tent poles, and all manner of sundry items for which His Majesty’s Government holds me accountable. I have dispatched reports on the character, wit and spleen of every officer. Each item and every farthing has been accounted for with two regrettable exceptions for which I beg your indulgence.

Unfortunately the sum of one shilling and ninepence remains unaccounted for in one infantry battalion’s petty cash and there has been a hideous confusion as to the number of jars of raspberry jam issued to one cavalry regiment during a sandstorm in western Spain. This reprehensible carelessness may be related to the pressure of circumstance, since we are at war with France, a fact which may come as a bit of a surprise to you gentlemen in Whitehall.

This brings me to my present purpose, which is to request elucidation of my instructions from His Majesty’s Government so that I may better understand why I am dragging an army over these barren plains. I construe that perforce it must be one of two alternative duties, as given below. I shall pursue either with the best of my ability, but I cannot do both:

1.) To train an army of uniformed British clerks in Spain for the benefit of the accountants and copy-boys in London or, perchance…
2.) To see to it the forces of Napoleon are driven out of Spain.

Your most obedient servant,
Wellington

While it is important to ensure that taxpayers' resources are well looked after, the fog of war is always likely to result in some wastage and administrative discrepancies - though £6.3bn is quite a discrepancy! But I suggest that the even more important question is about the overall mission - the desired effect - rather than the flaws in the associated administrative processes.

After all, what use is good book-keeping if you lose the war?

Footnotes:
See also Evelyn Waugh's letter to his wife about explosive military mathematics.
The 6th Duke of Wellington was killed in action while serving with No. 2 Commando in 1943.
Thanks to Alex Jacobs of NGO Performance for reminding me of Wellington's letter.