Re:6 is the prophecies about what the trumps see manifest as reality. For the ones that come under judgment (all of mankind that is alive at the moment) was is not permitted and I assume that means just belonging rather than having to be in the thick of battle. Perhaps if you help build a tank you suffer the same fate as the 'tank crew'. If you have personal choice then that is not being in the army and 'civilians' are still under a directive, especially in that last period of time.

1Pe:4:12-18:
Beloved,
think it not strange concerning the fiery trial which is to try you,
as though some strange thing happened unto you:
But rejoice,
inasmuch as ye are partakers of Christ's sufferings;
that,
when his glory shall be revealed,
ye may be glad also with exceeding joy.
If ye be reproached for the name of Christ,
happy are ye;
for the spirit of glory and of God resteth upon you:
on their part he is evil spoken of,
but on your part he is glorified.
But let none of you suffer as a murderer,
or as a thief,
or as an evildoer,
or as a busybody in other men's matters.
Yet if any man suffer as a Christian,
let him not be ashamed;
but let him glorify God on this behalf.
For the time is come that judgment must begin at the house of God:
and if it first begin at us,
what shall the end be of them that obey not the gospel of God?
And if the righteous scarcely be saved,
where shall the ungodly and the sinner appear?