and how it's used by B'tselem in Gaza. B'tselem didn't lie - they never lie. I found a passage in the ICRC report that explains why it's contrary to IHL to automatically assume that some civilians are to be considered combatants at all times:
INTERPRETIVE guidance on the notion of Direct participation in hostilities under international humanitarian law
Source: ICRC, 2009
(snip p44-45)
Where civilians engage in hostile acts on a persistently recurrent basis, it may be tempting to regard not only each hostile act as direct participation in hostilities, but even their continued intent to carry out unspecified hostile acts in the future. However, any extension of the concept of direct participation in hostilities beyond specific acts would blur the distinction made in IHL between temporary, activity-based loss of protection (due to direct participation in hostilities), and continuous, status or functionbased loss of protection (due to combatant status or continuous combat function). In practice, confusing the distinct regimes by which IHL governs the loss of protection for civilians and for members of State armed forces or organized armed groups would provoke insurmountable evidentiary problems. Those conducting hostilities already face the difficult task of distinguishing between civilians who are and civilians who are not engaged in a specific hostile act (direct participation in hostilities), and distinguishing both of these from members of organized armed groups
(continuous combat function) and State armed forces.
In operational reality, it would be impossible to determine with a sufficient degree of reliability whether civilians not currently preparing or executing a hostile act have previously done so on a persistently recurrent basis and whether they have the continued intent to do so again. Basing continuous loss of protection on such speculative criteria would inevitably result in erroneous or arbitrary attacks against civilians, thus undermining their protection which is at the heart of IHL. Consequently, in accordance with the object and purpose of IHL , the concept of direct participation in hostilities must be interpreted as restricted to specific hostile acts.
Read more:
https://www.icrc.org/eng/assets/files/other/icrc-002-0990.pdf