Mass Without Depth Is Temporary
“A thousand aircraft orbiting outside an adversary’s engagement envelope do not provide the combat power of a hundred able to penetrate it.” By Robbin Laird.
That was the core of Lt Gen David Deptula’s argument at the Sir Richard Williams Foundation’s 1 October seminar in Canberra, The Requirement for Air Combat Mass and Depth in the Indo-Pacific. He made it in conversation with Air Marshal Geoff Brown.
As air forces rebuild combat power and add collaborative combat aircraft and other autonomous systems, the temptation is to count tails and compare unit prices.
It is an attractive way to think about mass.It is also the wrong measure.
Deptula’s case turns on a few distinctions:
Mass is an effect, not a count. The test is how many relevant effects a force can generate, at what distance, against what opposition, and for how long.
Depth is what makes mass last. Weapons, spare engines, maintainers, fuel and basing decide whether a force is a campaign instrument or a one-week demonstration.
Attritable is not the same as affordable. Attritability is about risk. Affordability is about resources. A force built around expected loss ends up competing on the industrial ground where China is strongest.
CCAs are enablement, not substitution. The question is not whether an F-47 can be replaced by three cheap aircraft. It is what an F-47 working with autonomous aircraft can do that neither could do alone.
For Australia, distance is “one of the defining characteristics of the problem.” Range, survivability and weapons depth are requirements, not luxuries.
My own addition is that the real contest is between enterprises, not platforms. The side better able to regenerate effects under pressure holds the advantage. That is a harder metric than unit price, and a more honest one.
The question for air forces is not crewed versus uncrewed, or high-end versus low-cost. It is whether they will start from the effects required to win, test what the new systems can deliver, and resource the force the strategy demands.
Read the full analysis: https://defense.info/featured-story/2026/10/mass-without-depth-is-temporary/
