How would you explain this phrase?
The colonel gestured toward the LT, extending his arm out to him, palm up. “Lieutenant, they are all yours.”
“Thank you, sir.” He cleared his throat three times. “All right, boys, we’ll be on fifty-percent security tonight. We move from this position just before light, crossing the open ground out there while we still have the cover of darkness.”

How would you explain this phrase: on fifty-percent security?
Thanks!

Question

How would you explain this phrase?
The colonel gestured toward the LT, extending his arm out to him, palm up. “Lieutenant, they are all yours.”
“Thank you, sir.” He cleared his throat three times. “All right, boys, we’ll be on fifty-percent security tonight. We move from this position just before light, crossing the open ground out there while we still have the cover of darkness.”

How would you explain this phrase: on fifty-percent security?
Thanks!

Answer

I would say that "fifty percent" security here denotes a level of vigilance/security. In other words, think of the code green, code blue, code yellow, code orange, and code red system for "terrorism threat" in the United States. (I made up code blue, just so that code yellow can be in the middle). The military in your paragraph is probably on "code yellow" (or half the maximum security level) for that night.

Answer

It seems as though he's saying that half (literally fifty percent) of their nightly duty is to maintain security/order.

Answer

It seems they are near enemy territory or passing a treacherous road, thats way they are on low security level. Half security level.

Answer

It means that at any one time half the guard are vigilant, guarding.