My biggest issue with the General's statement, though, was that you can't instantly make up for thousands of hours of lost training.
His point was not cutting training to zero, he was saying that the Service Chiefs have three ways to cut spending. These three dials must be used like rheostats by taking more of an 'analog' approach to cost cutting. Each dial has a large range, it's not a digital 1/0 signal.
His quote: "As we shrink our force to pay the bill, we only have three ways that we can pay bills. One is in procurement, one is in personnel, and the other one is operations and maintenance. So you can dial those three dials in any combination, but there are three dials that we have."
Or
listen to it; go to time 41:45 to hear him say it.
What he was trying to explain was that the dials can all be turned simultaneously to effect a cost savings.
If you cut manning, then you have gaps in the manpower pool that can not be repaired or replaced. (T-notch/Son of T-notch, etc)
If you cut acquisition funding you have two issues, first is sunk-cost of what you've put into it. The second is you may never get the program/capability back after you cut it.
Turning down these two 'dials' may look appealing to Congress today but there is a significant price to pay later on down the road. He was warning against robbing Peter (future manning/programs) to pay Paul (OPTEMPO).
If you cut OPTEMPO than you feel the impact immediately, BUT unlike the other two, this capability can be repaired/replaced. You can not replace a year group that never accesses or an aircraft/ship/sub/weapon systems that you do not buy. You can make up for missed/cancelled training in the future.
I don't think the Commandant was telling Congress that there is ZERO impact to cutting OPTEMPO. What he was doing was cautioning the lawmakers that there is no simple answer to cutting defense spending. How long do you want to feel the pain and where do you want that pain.
Not to put words into his mouth, but IMO he was suggesting a balanced cutting program is cutting some OPTEMPO (reducing the demand signal for military forces TODAY) with looking at savings in the future that will come from trimming back the size of the force while at the same time looking for savings in the acquisition process.