"It'll get better when things calm down"
You've had the row more since the baby, or since the move, or since one of you changed jobs and the hours got worse. So the belief is that it's circumstances, and when they ease, the row will ease with them. Get through this year. It'll be different when they're at school.
Brian Doss and colleagues followed two hundred and eighteen couples through the first eight years of marriage, and compared those who had a first child with those who didn't. After the birth, parents showed a sudden drop in how well the relationship was functioning, on what they reported and on what observers saw, and the drop was small to medium in size and, this is the part, it tended to persist for the rest of the study. Mothers and fathers changed about the same amount. The couples without children declined too, more gradually, without the sudden step. So the baby did make it worse, and the worse didn't lift when the baby became a toddler.
I'd read that alongside the costume idea. Circumstances don't cause the one row. They change its costume and its frequency. Before the baby it was the weekend plan. After the baby it's who got up in the night, and it's more often, because both of you are more tired and the underneath is nearer the surface, as chapter 10 said. When things calm down, the frequency may drop, and the costume will change again, and the row will be waiting under the new one, because it travels. It travelled from your first flat to this house. It'll travel to the next.
That's not a counsel of despair. It's the opposite. If the row were caused by circumstances, you'd have to wait for them, and the waiting is its own strain, because every instance during the wait is a reminder that the calm hasn't come. If the row is the two of you, then it's available to be handled now, this Tuesday, in this kitchen, with the baby monitor on the side. You don't need things to calm down to say the name. You need to say the name, and things will be a bit calmer for it.
Chapter 24 has a case for the couple since the baby, because that period does need some adjustments to the method. But the belief here, that the row is a phase, is worth putting down, because the phases change and it doesn't.