Missing from most of the commentary on the Secretary of Defense’s big defense spending speech yesterday is the fact that the program cuts he proposed are largely a result of freezing the topline — keeping defense spending level (once you adjust for inflation) for the next decade.

For nearly a decade the country has really had two defense budgets – one for imagined conventional wars against states like China, another from nation-building, peacekeeping and counterinsurgency. The first budget requires a small ground force and lots of big platforms operated by the Air Force and Navy. The latter requires much larger ground forces, a few niche capabilities like intelligence, surveillance and reconnaissance aircraft, and less high technology wonders.

The current American love affair with counterinsurgency has resulted in a gradual shift of dollars from the conventional budget to the unconventional one. We are reversing the old idea that the American way of war is to replace labor with capital, or manpower with technology. We are becoming a land power first. We have been increasing manpower in the Army and Marines — adding 90,000 new troops — and paying them way more (compensation per service member is up by almost half since 1998). Personnel costs are taking more of the budget. And for more complex reasons, including health care costs, the operations and maintenance part of the budget — essentially the day to day cost of running the military — has also been growing fast when measured per service member. (For details on these issues, read this testimony by Stephen Daggett of the Congressional Research Service.)

That was bound to squeeze the other big parts of the defense budget — research, development and procurement of new weapons systems. There is too much future cost in the budget for everything to fit without topline growth, so something had to give. Big weapons programs are where the most give is, if you don’t want to cut manpower.

That conflict was delayed while the budget topline grew, but now that it is flat, it erupts. The manpower intensive military that follows from our current policies is eating into the conventional military that delivers manufactoring jobs across the country and the high-technology dreams of our military leaders.

What will be interesting to see is whether this shift encourages those leaders and their friends on the Hill to take up the arguments that people like me have been making for years: that small wars are mostly dumb wars. Preparation for these wars didn’t much hurt the military industrial complex before, now it does.

An additional note: Gates’ criticism of the acquisition process was on the mark. Rather than blaming out of control weapons costs on the kind of contracts we write or crafty contractors, as the President seems to, Gates noted correctly that the trouble is the requirements process — what we want, not how we buy it.