Thanks Jeff for the elaborated answer.

It seems that the justification for mapping the DMZ line is for historic and/or future purposes, as you wrote:
> 

For the DMZ, none of the main parties currently claim it as their border, but it is one possible border with some historical precedent.

boundary=historic says:
> Note that though solely historic objects should not be mapped as it is outside of scope of OSM (unlike projects like Open Historical Map), it makes sense to keep for some time old boundaries after administrative division change as form of note to make clear that there was a recent change of borders in a given location.

Since this line does not have, AFAIK, any on-the -ground presence for more than 50 years, I suggest this relation to be removed from OSM. You may choose to copy it to Open Historical Map.

You also wrote:
> So for rendering here, the intent is for uninvolved viewpoints to see it as a dashed line showing it as one of several possible borders.

I believe that OSM is not the appropriate platform for rendering potential political solutions for this decades-old conflict.

@BodhidharmaI see the source tag for this changeset -
https://www.loc.gov/item/92682948/

May I add that relation/13574166 is a strange disputed boundary. I believe a boundary cannot be "disputed" when it is not "claimed_by" any country.

Specifically, Syria is not claiming this boundary. The Syrian claims were apparently mapped by relation/13574167

Your questions are:

Q1. What does "disputed_by" represent here (at the boundary of a DMZ)?
A1. This question should be directed to the original mapper.

Q2. Does it mean DMZ itself is not recognized by these countries?
A2. This question should be directed to the original mapper.

Q3. In which case, why IL?
A3. This question should be directed to the original mapper.

Q4. Or does it mean the boundary is disputed (i.e. the disputing countries believe it should be elsewhere)?
A4. This question should be directed to the original mapper.

I've copied your question to the discussion of the original changeset for the original mapper to be aware of them and respond.

The way to address your questions is through a discussion with the original mapper, not using fixme tags.

In changeset/120591354
user BodhidharmaI placed several questions in the fixme tag for the relation "1949 Israeli–Syrian DMZ"
relation/13574166 :

1. What does "disputed_by" represent here (at the boundary of a DMZ)?
2. Does it mean DMZ itself is not recognized by these countries?
3. In which case, why IL?
4. Or does it mean the boundary is disputed (i.e. the disputing countries believe it should be elsewhere)?

I believe these question belong here and not in the fixme tag.

The comments sure looks like a beginning of a discussion. It consists of 4 questions and and not a single answer.

The questions should be placed in the discussion for the original changeset -
changeset/115187152.

Please avoid using the fixme tag for discussions.

Hello,

Please note that in this and other edits in this area you have broken several turn restriction relations.

Please see
https://overpass-turbo.eu/s/1jwJ
for the list of the affected relations

Hello,

Note that in this edit you have broken a turn restriction relation
relation/12948954

Hello,

Note that in this edit you have broken several turn restriction relations:
relation/14078186
relation/14078187
relation/14078189

Hello,

Note that in this edit you have broken a turn restriction relation
relation/13338172

Hello kflux,

Thanks for updating OSM!
During your update you have removed the 'highway' tag of the path.

Please set the appropriate value for the highway tag: path, footway, track, etc.

Also, this discussion on Facebook
https://www.facebook.com/groups/israelhikingmap/permalink/4139372262784602/

Checkout changeset/102851367

Which geometries do you want to delete?
Why do they suck?

להבנתי, צו אלוף זו לא הכרזה

Fixed in changeset/121778035

I've added the missing building tags, fixed open geometries, and removed irrelevant tags added to some nodes.

Hello,

There is a well-established guidelined for hiking and biking trails in Israel. Please see osm.wiki/Israel#Conventions_for_hiking_and_biking_trails

According to these guidelines, each trail is a separate relation. This is especially applicable where each trail has a different name and/or colour.

Are there any problems other than un-tagged ways? They all seem to buildings?