"To me it is a sin to kill a man. Even Fascists whom we must kill. To me there is a great difference between the bear and the man and I do not believe the wizardry of the gypsies about the brotherhood with animals. No. I am against all killing of men."
"Yet you have killed."
"Yes. And will again. (3.66-68)
Anselmo is the character who feels most strongly that killing is wrong, and the one who says so most often. He's a hunter, and takes pleasure in the hunt, but believes there is a great difference between human beings and animals. That point keeps coming back in the book (check out what we have to say about animal metaphors in the "Symbols, Imagery, Allegory" section). He also never stops using religious language – killing is a "sin" – even though he's given up religion. Yet he's somehow reconciled to the necessity of killing.
To kill them teaches nothing," Anselmo said. "You cannot exterminate them because from their seed comes more with greater hatred. Prison is nothing. Prison only makes hatred. That all our enemies should learn." (3.81)
Anger and vengefulness play little part in Anselmo's opposition to the fascists. He genuinely wants them to learn, and thinks (as we find out elsewhere) that if they could only understand how hard life is for many of the working people of Spain, they would change. War doesn't teach people anything, because it only leads them to keep fighting, fuelled by rage. You could imagine the same convictions leading to a pacifist stance; it's interesting, and maybe a little problematic, that Anselmo chooses to fight.
"Clearly," the woman said. "If you want it that way. Perhaps it came from talking that foolishness about Valencia. And that failure of a man who has gone to look at his horses. I wounded him much with the story. Kill him, yes. Curse him, yes. But wound him, no." (9.46)
Is Pilar genuinely willing to kill Pablo? That's a hard question to answer throughout the book. It's clear from this, however, that she still feels sympathy for him: she's feeling guilty that she deliberately tried to injure him by comparing him badly to an earlier over. She seems to suggest that it's worse to take away a man's dignity than it is his life. There's a similarity in this to some of the thoughts on how one should kill voiced by other characters (including herself).
"'Why is this done thus, Pilar?' he [Pablo] said to me.
'To save bullets,' I [Pilar] said. 'And that each man should have his share in the responsibility.'" (10.135-6)
Pablo's idea in having the townspeople execute the fascists together, if it seems brutal, is also meant to be just – given that all of the townspeople are involved in the war together and want to benefit from the liberation of their town, it's only right that they should share responsibility for killing their enemies. Otherwise, the fighters (like Pablo) would do all the dirty work, while the townspeople would benefit from the outcome of it.
"It was a thing of great ugliness, but I had thought if this is how it must be, this is how it must be, and at least there was no cruelty, only the depriving of life which, as we all have learned in these years, is a thing of ugliness but also a necessity if we are to win, and to preserve the Republic.
When the square had been closed off and the lines formed, I had admired and understood it as a conception of Pablo, although it seemed to me to be somewhat fantastic and that it would be necessary for all that was to be done to be done in good taste if it were not to be repugnant. Certainly if the fascists were to be executed by the people, it was better for all the people to have a part in it, and I wished to share the guilt as much as any, just as I hoped to share in the benefits when the town should be ours. But after Don Guillermo, I felt a feeling of shame and distaste, and with the coming of the drunkards and the worthless ones into the lines, and the abstention of those who left the lines as a protest after Don Guillermo, I wished that I might disassociate myself altogether from the lines, and I walked away, across the square, and sat down on a bench under one of the big trees that gave shade there." (10.255-256)
After all is said and done, Pilar doesn't find that Pablo's idea of "sharing the responsibility" made the killings acceptable. People who did not deserve to die (Don Guillermo) were killed. Her evaluation is also affected by how she judges the killers themselves: part of what disgusts her is that the many of the people participated were drunkards (who would presumably never have the courage to fight, or the poise to face their own death as some of their enemies did). Pilar's judgment is partially motivated by considerations of honor.
Across the road at the sawmill smoke was coming out of the chimney and Anselmo could smell it blown toward him through the snow. The fascists are warm, he thought, and they are comfortable, and tomorrow night we will kill them. It is a strange thing and I do not like to think of it. I have watched them all day and they are the same men that we are. I believe that I could walk up to the mill and knock on the door and I would be welcome except that they have orders to challenge all travelers and ask to see their papers. It is only orders that come between us. Those men are not fascists. I call them so, but they are not. They are poor men as we are. They should never be fighting against us and I do not like to think of the killing. (15.7)
So many of the enemies the Republicans are fighting are not really "fascists," if by "fascist" one means someone who truly believes in fascist ideology. This Anselmo finds very troubling. There seem to be far more similarities between himself and his enemies than differences – at base just because they're human beings. What divides them is artificial, just "paper." Think back to that epigraph idea of all humans being tied together somehow.
I've probably seen him run through the streets ahead of the bulls at the Feria in Pamplona, Robert Jordan thought. You never kill any one that you want to kill in a war, he said to himself. Well, hardly ever, he amended and went on reading the letters. (26.3)
Robert Jordan sounds like Anselmo here. He had no desire to kill the patrolman he shot that morning, and no reason to other than his "orders." He was a fascist only because of the allegiance of his region, Navarra, and his loyalty to the Catholic Church (as a Carlist). Navarra is one of Robert Jordan's favorite regions of Spain, and it's particularly saddening for him to kill one of its native sons. What must it feel like for a Spaniard to kill another Spaniard, then?
But it would not drop that easily. How many is it that you have killed? He asked himself. I don't know. Do you think you have a right to kill any one? No. But I have to. How many of those we have killed have been real fascists? Very few. But they are all the enemy to whose force we are opposing force. But you like the people of Navarra better than those of any other part of Spain. Yes. And you kill them. Yes. If you don't believe it go down there to the camp. Don't you know it is wrong to kill? Yes. But you do it? Yes. And you still believe absolutely that your cause is right? Yes.
It is right, he told himself, not reassuringly, but proudly. I believe in the people and their right to govern themselves as they wish. But you mustn't believe in killing, he told himself. You must do it as a necessity but you must not believe in it. You must do it as a necessity but you must not believe in it. IF you believe in it the whole thing is wrong. (26.20-21)
This is about as definitive a statement as we'll get of Robert Jordan's feelings about killing. He can't admit that killing in itself is ever right, but he feels it's necessary. And that's because he's convinced the Republican political cause is right. To minimize the injustice of killing, however, the killer can't take pleasure in it. And should kill as few people as possible. It's interesting to note, though, that Robert Jordan doesn't seem to have strong feelings, or disgust, about killing in the way that Pilar or Anselmo do. His disagreement seems to be more intellectual, more on principle, and less emotional.
He heard her breathing steadily and regularly now and he knew she was asleep and he lay awake and very still not wanting to waken her by moving. He thought of all the part she had not told him and he lay there hating and he was pleased there would be killing in the morning. But I must not take any of it personally, he thought.
Though how can I keep from it? I know that we did dreadful things to them too. But it was because we were uneducated and knew no better. But they did that on purpose and deliberately. Those who did that are the last flowering of what their education has produced. Those are the flowers of Spanish chivalry. (31.163-164)
It's after Maria describes her rape to Robert Jordan that he first shows signs of the bloodlust that other characters like Pablo and Agustín have already felt. He tries to think his way out of it by recognizing that both sides have done horrible things to each other. But thinking also leads him to one difference he thinks is morally relevant between the Republicans and the fascists: many of the Republican brutalities have been done by the poor and uneducated (who are trying to defend what little they have), whereas the fascists, who represent the upper class, should know better, and have higher standards.
"You're not going to kill any of us, are you?" Agustín said. "For I will kill thee now."
"Shut up," Pablo said. "I have to look after thy interest and that of the band. This is war. One cannot do what one would wish." (43.238-239)
Agustín is obviously disgusted by Pablo's murder of the men he brought with him. But Pablo's justification is that he was looking after the interests of their own band, since otherwise not all of them would be able to escape. Pablo's loyalties to his own small group are clearly much stronger than any duty he feels to his companions in the Republican cause; he's not only willing to kill fascists, he's willing to kill allies for the sake of his "tribe's" safety. Like those troubled by killing fascists, he ultimately lays the blame on the war situation itself.