The old man has already walked twelve kilometers away from his home town San Carlos. He is sitting in dust on the road side close to a bridge on the River Ebro. He is worried about his animals that include a cat, two goats and four pairs of pigeons; they also constitute his family.
The troops have forced him along with others to vacate his home town as the enemy was approaching fast to carry out a massive attack.
“Trucks up the road” would take him towards Barcelona, if he boards one. Several of them have been deployed to take the civilians to safe places. But the old man doesn't want to go further.
When the narrator urges him to leave the place, the old man says, "Thank you," and gets to his feet but instead of going along with him, he
“…swayed from side to side and then sat down backwards in the dust.”
The old man's dilemma is about making a decision over either to proceed towards Barcelona where he knows “no one in that direction" or to await his fate sitting lonely and thinking about his mute family members.
His dilemma shows how deep his attachment is to his animals. The fact that he is putting his life in danger by not moving further doesn't seem to bother him much. Although he has come miles away from his animals, he is simply unable to move ahead without them.
Besides, his dilemma makes him a foil to the remorseless and cruel enemy who won’t hesitate to open indiscriminate firing on the civilians, soldiers and even animals and birds alike.