The second important piece is here: First, based on warfighting experience over the past several years and judgments about future threats, the Defense Department is revisiting the scenarios on which the Air Force based its assessment.

Read this in conjunction with the paragraph before it, which states that Donley and Schwartz concluded last summer that a 381-aircraft force was "low-risk" and that 243 was "moderate risk". It's not a huge logical leap to say that 183 was termed "high risk" - that is, likely to prove deficient against future threats.

The USAF has not changed its methodology, but the DoD "is revisiting the scenarios" - that is, changing the inputs to the process. That is of course the DoD's job; but the Gates team seems to have done this in only one specific case. And when was it done? As we've reported before, the USAF in March was saying that it needed more F-22s.

Third pivotal comment: Analysis showed that overlapping F-22 and F-35 production would not only be expensive but that while the F-35 may still experience some growing pains, there is little risk of a catastrophic failure in its production line.

In its simplest terms, whether a risk is acceptable or not depends on the level of risk - its probability - and its consequences. Most of us will buy a $1 raffle ticket for a $50 prize even if we know that 100 tickets have been sold. Russian roulette has a much higher chance of a "win" - five in six - but most of us won't do that. That's risk management.

Now define "catastrophic". If you mean, for example, that JSF unit cost doubles and production rates are halved - as has happened to a lot of programs - there may be "little risk" of this. But its effect in a fixed-budget world would be to gut the US Air Force: the consequence is so severe that the only acceptable level of risk is zero.

Far lesser, and more likely JSF problems - a further delay in flight testing, more moderate increases in cost and rate reductions - will have a major impact because of the project's size and because there's no backup plan.

They could accelerate the aging of the force, compel the USAF to shrink its front-line strength and starve the other needs - nuclear reconstitution, ISR, space and cyber - that the two USAF leaders mention in the WaPo piece. Indeed, a two-year slip and a 25 per cent overrun in the price tag would easily equal the cost of 60 more F-22s over the same period of time.

But finally, missing from this piece is the full byline: Michael Donley is secretary of the Air Force. Gen. Norton Schwartz is chief of staff of the Air Force. Both were appointed to their present positions by SecDef Gates last summer, after he fired their predecessors, who had argued in favor of more F-22s.