That's your third completely unconnected argument, and this one doesn't make Japan and return missions assuming viability of straw drawing rational either. Even if the pilots are rationally maximizing some combination of survival and military glory that doesn't mean Japan bombing and return missions with most of the load devoted to fuel are an efficient way to gain it. You could have all pilots volunteering to be part of the draw for one way missions and those who draw long being reassigned to Europe or whereever they can earn glory more fuel efficiently.

Say you start out with 100 pilots. You have two options:

1. Send all 100 pilots to Japan with full fuel tanks. 25 make it back alive.
2. Send 50 pilots to Japan with twice as many bombs. 0 make it back, but 50 are still alive.

the military wants to recoup that cost by sending everyone they bother to train out on a certain number of missions.

No, the military just wants to accomplish its missions. If more pilots are alive after each mission, it means more pilots available for future missions.

Honest questions are far less likely to be voted down than wrong statements.

When the general case seems confusing, it's often helpful to work out a specific example.

Let's say that there are 40 targets that need to be bombed, and each plane can carry 10 bombs normally, or 20 bombs if it doesn't carry fuel for the return trip. We'll assume for simplicity that half of the bombs loaded on a plane will find their targets (accounting for misses, duds and planes shot down before they're finished bombing).

Then, with the normal scheme, it would take eight flights on average to bomb the forty targets, and six of those planes would go down. If instead the planes were loaded with extra bombs instead of return fuel, it would take only four such flights (all of which would of course go down).

If there are eight flight crews to begin with, drawing straws for the doomed flights gives you a 50% chance of surviving, whereas the normal procedure leaves you only a 25% chance. If those are all the missions, it's clearly rational to prefer the lottery system to the normal one. (If instead the missions are going to continue indefinitely, of course, you're doomed with probability 1 either way.) And of course the military brass would be happy to achieve a given objective with only 2/3 the usual losses.

The difficulty with thinking in terms of "half-lives of danger" is that it's the reciprocal of your probability of survival, so if you try and treat them as simple disutilities, you'll run into problems. (For instance, if you're facing a coinflip between dangerous activities A and B, where A consists of one half-life of danger and B consists of five half-lives, your current predicament is not equivalent to the "average value" of three half-lives of danger.)