question:  What is ironic about Russell's decision to kill Dunbar?
context: TO EACH HIS STAR by BRYCE WALTON "Nothing around those other suns but ashes and dried blood," old Dunbar told the space-wrecked, desperate men. How could they believe in his choice when every star in this forsaken section of space was surrounded by a beckoning red rim? Russell didn't think they could remain sane in all this blackness much longer. Dunbar, the oldest of the four, an old space-buster with a face wrinkled like a dried prune, burned by cosmic rays and the suns of worlds so far away they were scarcely credible, had taken command. Four men, thought Russell, held together by an invisible string of gravity, plunging through a lost pocket of hell's dark where there had never been any sound or life, with old Dunbar the first in line, taking the lead because he was older and knew where he was and where he was going. But Russell knew it and he'd admitted it from the first—that old Dunbar was as crazy as a Jovian juke-bird. Russell had no idea now how long the four of them had been plunging toward the red-rimmed sun that never seemed to get any nearer. And Russell was looking at Dunbar's suit up ahead, watching it more and more intently, thinking about how Dunbar looked inside that suit—and hating Dunbar more and more for claiming he knew when he didn't, for his drooling optimism—because he was taking them on into deeper darkness and calling their destination Paradise. When the four of them had escaped from that prison colony on a sizzling hot asteroid rock in the Ronlwhyn system, that wasn't enough for Dunbar. no—Dunbar had to start talking about a place they could go where they'd never be apprehended, in a system no one else had ever heard of, where they could live like gods on a green soft world like the Earth had been a long time back. You said that one had a red rim, Dunbar, and I wanted to believe it.
output:  If the four men had followed Dunbar, they all would have survived.
options:  After killing Dunbar, Russell became just as delusional as Dunbar  If Russell had not killed Dunbar, the three men would have never reached their ultimate paradise  The four men were all going to die anyway, but they could have died together.  If the four men had followed Dunbar, they all would have survived.