I believe that any Israeli who chooses to be a settler in the occupied territories should automatically be termed a belligerent, and as such, should not be protected under any of the laws which protect civilians during conflict. Is there any precedent in international law (say from South Africa?) on this question?

Under international law, it is illegal to annex the territory of another; and under this law, both the permanent imposition of security forces, and the settler program, are illegal.

By living in the occupied territories, the settlers become part of an annexation program. Their presence is defended by military troops and police who do not enforce any laws against the settlers which means that if the settlers attack Palestinians, nothing happens to the settlers; but if the Palestinians defend themselves, they are met with military violence.

This adds up to a very clear case of exploiting a legal loophole. The settlers are usually armed, and very often aggressive; they are also given economic subsidies and military support; but since they are not formally enlisted themselves (or anyway not acting under acknowledged military orders in their capacity as violent settlers), they can ride on the "civilian" moniker. This seems to me a very clear circumvention of the spirit of international law, carried out by exploiting the loophole: that there is no legal framework whatsoever for handling illegal settlers in a case like this, that I know of. They may exist in such a legal blind spot -- and/or, it might be comparable to some precedent dealing with apartheid, occupation, ethnic cleansing, and/or displacement.

I accept that this is an extremely contentious question and can only hope some conversation happens in addition to the hasbara, the trolling, and the more-genuine reactionary comments.

While it is certainly horrible to consider the legitimization of attacking families in their home, doing so would represent Palestine being legally allowed to defend itself using the same tactics with which Israel illegally attacks Palestine. As the defender, Palestine should have more rights to "legally clean" combat options on the territory outside the Green Line, but existing "lawfare" has damaged that reality.

I look forward to contributions by anyone who would like to answer that lawfare in kind, on behalf of Palestine.

While I feel like everyone here probably knows all this stuff (whether they'd like to dispute it or not), here are some obligatory sources:

Annexation is illegal:

https://en.wikipedia.org/wiki/Annexation#International_law_after_1949

https://www.icrc.org/eng/resources/documents/faq/occupation-faq-051010.htm

Israeli authorities only enforce the law against Palestinians, not settlers:

https://www.icrc.org/spa/assets/files/review/2012/irrc-885-kretzmer.pdf

http://www.haaretz.com/print-edition/opinion/israel-must-enforce-law-on-west-bank-settlers-1.401268

The settlements are illegal:

http://www.huffingtonpost.com/osamah-khalil/above-the-law-israeli-set_b_763032.html

http://www.huffingtonpost.com/2013/01/31/un-panel-israeli-settlements-illegal_n_2589394.html

http://theconversation.com/settlements-illegal-under-what-law-take-your-pick-minister-22341

Thanks to mandatory conscription, most settlers have military experience:

https://en.wikipedia.org/wiki/Conscription_in_Israel

They are also frequently armed and violent:

http://www.independent.co.uk/news/world/middle-east/david-amos-gun-wielding-gang-of-israeli-settlers-attack-british-pro-palestinian-volunteer-in-west-a6693986.html

http://www.intifada-palestine.com/2015/10/david-amos-gun-wielding-gang-of-israeli-settlers-attack-british-volunteer-in-west-bank/

http://www.usatoday.com/story/news/world/2015/10/12/glocker-mom-other-israeli-settlers-carry-guns-amid-palestinian-violence/73811790/

http://www.theguardian.com/world/2012/may/21/israeli-settler-fires-gun-stone-thrower

Some carry out directed offensives called "price tagging" designed to destroy Palestinian living infrastructure:

http://www.adl.org/israel-international/israel-middle-east/content/backgroundersarticles/price-tag-attacks.html?referrer=https://www.google.com/#.ViIDjnWc2_o

https://en.wikipedia.org/wiki/Price_tag_policy