The ripple effect
In March 2022 I was stationery behind a school bus at a roundabout and got rear-ended by the driver behind me who was on their cellphone. Three months on there were still physical side effects from the whiplash.
Other implications from this (totally avoidable) situation:
How anxious I was driving straight afterwards.
How nervous I felt when cars drove behind me.
Holding my breath at roundabouts or intersections in anticipation.
How incredibly annoyed I got seeing anyone on the phone while they were driving.
Being in a car with someone else driving - couldn't relax.
What does this have to do with dogs?
Apply this train of thought to something that has caused them big feelings in the past. It doesn't have to actually be a big scary situation- they are individuals and what doesn't bother one dog could cause a panic attack in another - rather, an event that causes big feelings to that particular individual.
Monitoring body language and supporting the dog you have in front of you, not suppressing their behaviour is what's needed for long term success.
To help them, train for the situation not in it. If they have had upsetting experiences, a careful plan is needed because there could be certain things you haven't considered working against you. If you're not making progress (no matter how small) or you're not sure where to start - get help!