R.A.K. Mason, "Sonnet of Brotherhood"

Garrisons pent up in a little fort
  with foes who do but wait on every side
knowing the time soon comes when they shall ride
triumphant over those trapped and make sport
of them: when those within know very short
is now their hour and no aid can betide:
such men as these not quarrel and divide
but friend and foe are friends in their hard sort

And if these things be so oh men then what
  of these beleaguered victims this our race
betrayed alike by Fate's gigantic plot
here in this far-pitched perilous hostile place
this solitary hard-assaulted spot
fixed at the friendless outer edge of space.