The "Early Warning" or "Prior Warning" case from some 20 years ago, which [AFAICT] involved sending in a neighbor to demand surrender, is probably relevant.
Israel notes that the Supreme Court in Add. H.C.J. 10739/05 The Minister of Defense v. Adalah, The Legal Center for Arab Minority Rights in Israel, prohibited in the most sweeping manner the legality of this use of local residents. Subsequently, a General Staff Order was issued revoking the previous “Preliminary Warning” procedure and prohibiting every type of aid or assistance by local population. This Order is fully adhered to by IDF forces, and every violation results in criminal investigations.
I haven't found that (Adalah – The Legal Center for Arab
Minority Rights in Israel v. GCO Central Command, IDF) full case in English, but from a summary in another it appears the Supreme Court took a broad interpretation of Fourth Geneva Convention §27 and Hague Regulations §46 to prohibit involving the local civilian population in such auxiliary roles for the IDF. If you read the full text of those invoked provisions, it's actually not that clear that they entail such a prohibition, but the Supreme Court of Israel read them that way. E.g. regulation 46 (quoting that as it's shorter) says:
Family honour and rights, the lives of persons, and private property, as well as religious convictions and practice, must be respected.
Private property cannot be confiscated.
The most relevant bit from Art 27 is probably
Protected persons [...] shall at all times be humanely treated, and shall be protected especially against all acts of violence or threats thereof and against insults and public curiosity.
FWTW, the same Israeli reply to the UN mentioned:
In 2007, nine investigative military police investigations were conducted regarding claims of such violations; in 2008, no investigations were held. Up to now, no indictments were filed regarding these cases, due to lack of evidence concerning these allegations. In 2009, to date, four investigations are conducting following the events of operation “Cast Lead”.
N.B. I (finally) found the actual full-text decision in that case. The most relevant bits are paras 21-25 from President Barak's judgment. Unfortunately, even those parts are quite long (2 pages in relatively small print/font), so I quote only a selection:
[...] The civilian population is not to be used for
the military needs of the occupying army (see Fleck, at p. 218). They are not to be
"volunteered" for cooperation with the army (see regulation 23(b) of The Hague
Regulations and article 51 of The Fourth Geneva Convention; see also Pictet, at p.
292). From this general principle is derived the specific prohibition of use of local
residents as a "human shield". Also derived from this principle is the prohibition of
use of coercion (physical or moral) of protected persons in order to obtain intelligence
(article 31 of The Fourth Geneva Convention; Pictet, at p. 219). It seems to me that
prohibiting use of local residents for relaying warnings from the army to those whom
the army wishes to arrest should also be derived from this general principle. Second,
an additional principle of the humanitarian law is that all is to be done to separate
between the civilian population and military activity (see Fleck, at p. 169). The
central application of this rule is the duty to distance innocent local residents from the
zone of hostilities (see rule 24 of International Humanitarian Law). This rule calls
for an approach, according to which a local resident is not to be brought, even with his
consent, into a zone in which combat activity is taking place. Third, in light of the
inequality between the occupying force and the local resident, it is not to be expected
that the local resident will reject the request that he relay a warning to the person
whom the army wishes to arrest. A procedure is not to be based upon consent, when
in many cases the consent will not be real (see Fleck, at p. 252). The situation in
which such consent would be requested should be avoided. Last, one cannot know in
advance whether the relaying of a warning involves danger to the local resident who
relays it. The ability to properly estimate the existence of danger is difficult in
combat conditions, and a procedure should not be based on the need to assume a lack
of danger, when such an assumption is at times unfounded. On this issue, one must
consider not only the physical danger of damage from gunfire originating in the
wanted person's location, or from various booby-traps, but also the wider danger
which a local resident who "collaborates" with the occupying army can expect.
These considerations lead me to the conclusion that the "Early Warning"
procedure is at odds with international law. It comes too close to the normative
"nucleus" of the forbidden, and is found in the relatively grey area (the penumbra) of
the improper.
There are two concurring opinions from other judges that add some additional arguments and no dissenting ones AFAICT.
