Term for 'going back to fight an old war'?

Question

Is there any phrase that figuratively yet succinctly captures the meaning of 'going back to do something difficult that has been done in the past yet has never been resolved'?

For example, imagine a never-ending debate over some political issue. The two sides have temporarily decided to put the issue on hold but eventually go back at it again (although there is hardly any hope for resolution).

'Going back to fight an old war' (that I mention in the title) seems to be one way to say this.

'Going back to the old trenches' seems to be another.

But I am wondering whether there is an even simpler and perhaps commonly used way to express this in literature/ writing?

Edit: Clarified that I am looking for a figurative expression and I added an example of a situation that would satisfy the expression.

Answer 1

I can’t really think of an idiom that combines both the idea of returning to an argument, and the fact that in doing so there is no hope of resolving it. However I offer some phrases that apply to just a single aspect of this.

The idea of the argument or conflict being old is contained in the following:

“Flogging a dead horse”

But this has the idea of continuation rather than return.

“Still fighting the last war”

Likewise, but with the idea that the tactics are inappropriate to current circumstances.

“An old chestnut”

This is just a description of something old and uninteresting

“Raking over the coals”

Although this refers to the action, it might be used to construct a phrase, such as “Going back to rake over the coals”. Not brilliant.

The idea of return is expressed in:

“(Re)opening old wounds”

But a wound is hardly an argument.

“Dusting off”

I suppose you might dust off an old argument. It hardly conveys the idea of re-engaging.

“Have another crack at…”

This might work followed by something like “resolving the problem”, although the latter is not idiomatic.

“Once more into the breach…”

Certainly military, but a little flowery for everyday use.

Can I stop now?

Answer 2

You can [finally] put the matter to bed (or attempt to).

put something to bed [phrase]

to finish dealing with something

• I hope we can finally put this issue to bed.

[Macmillan]

Answer 3

Relitigate the past

Technically, litigation refers to a fight in court rather than a war, but since you are speaking metaphorically, it has the same effect. The term "relitigating the past" can refer to rehashing an old fight of any kind.