I am 'annoyed' by the arguments brought forward in debates about military (don't call 'em "defense"!) budgets.
Here are some typical and outright idiotic approaches that 'some' people take:
We have x.y % GDP spending, so we can easily afford z %!
Last year we had x %, we should not reduce that!
Air force, army and navy need the same share of the budget!
The budget is full of waste, but to reduce it means to increase risks!
We are a maritime nation, so we need a huge navy!
We dreamed about a xyz ship navy for decades, so let's budget for this!
A country on the other side of earth spends x money on the military, so we need to spend x times ten money on the military!
Every department has to spend x % less this year, so has the military!
There's not enough tax revenue, so we need to spend less on the military (fuck the constant threats)!
Now let me lay out a kind of scientific approach to it, coined by knowledge about macroeconomics - especially about the concept of marginal rates:
Assess the most basic defence needs of the nation, and how much it costs to meet them.
Make a list of proposed additional military capabilities, and assess their (neutral estimate) cost/benefit ratio.
Look at the results from other departments, showing their proposed luxury shopping lists with attached neutral estimates of cost/benefit ratios.
Assess the state income system and its costs (including all economical costs, not only the state's administration costs. This includes the costs caused by distortions such as legal tax evasion and tax accountants turnover).
Now match up the most cost/benefit efficient proposals from all departments with the curve of increasing inefficiencies with increasing revenue. Spend on the most promising luxury shopping list items first, no matter which department.
At some point, to add an additional shopping list item would require the acceptance of so many economical damages from state revenue generation that it makes no sense from a national welfare point of view. Bureaucracies tend to go farther, of course.
See? I consider military budgets to be service budgets that serve the people of the nation. Expenditures on inefficient proposals hurts the national welfare and makes no sense whatsoever.
We may include the love of people for shiny fighter jets and big warships as emotional benefits in the cost/benefit assessment, but it's still subject to the analysis.
The lack of the attempt to actually optimise a budget for national welfare, instead going for various forms of bureaucratic interests and ideologies, is what annoys me.
1% GDP p.a. can be the difference between decline and prosperity if the choice is between adding it to public consumption (military) or to economic capital investment (adding to capital stock and thus to income generation over the next about 20 years).
Most -if not all- who debate on military budgets in public debate them as if those budgets were isolated. Only the basic needs can be de-coupled from other department's services. The luxury expenditures (and that's the majority in many NATO military institutions) need to compete with the services of other departments.
This isolated (and dumbed-down) discussion is the fatal flaw of most if not all debates on military budgets.