The title (!) of his article:
"Afghanistan: we owe it to all those who have sacrificed their lives to see this mission successfully concluded"
Compare sunk costs fallacy (quote Wikipedia):
Many people have strong misgivings about "wasting" resources (loss aversion). In the above example involving a non-refundable movie ticket, many people, for example, would feel obliged to go to the movie despite not really wanting to, because doing otherwise would be wasting the ticket price; they feel they've passed the point of no return. This is sometimes referred to as the sunk cost fallacy. Economists would label this behavior "irrational": it is inefficient because it misallocates resources by depending on information that is irrelevant to the decision being made. Colloquially, this is known as "throwing good money after bad".
The man is the Defence Secretary of the United Kingdom and he's incompetent.
Get rid of that fool!