LONDON — How much should a nation spend on defense and its armed forces?

A furious argument is now raging in Britain over this very question, with insults and criticisms flying between top military men and politicians about levels of defense spending, standards of equipment, soldiers' pay and pensions, costs of big projects, and much else.

Given the United Kingdom's traditional commitment to armed forces of the highest quality and a relatively high defense expenditure compared to neighboring European countries, and given the U.K.'s current commitments of troops at far-flung trouble spots, it might be expected that an expansion of military spending would be the priority.