This is not complex
Protocol I, Art., 51, Sec. 7
The presence or movements of the civilian population or individual civilians shall not be used to render certain points or areas immune from military operations, in particular in attempts to shield military objectives from attacks or to shield, favour or impede military operations. The Parties to the conflict shall not direct the movement of the civilian population or individual civilians in order to attempt to shield military objectives from attacks or to shield military operations. (Human Shields not allowed)
Protocol I, Art. 51, Sec. 5(b)
(b) an attack which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated. (Rockets shot by Hamas and Hezbollah, car bombs by Al Qaida set off in civillian areas)
Protocol I, Art. 37, Sec. 1
It is prohibited to kill, injure or capture an adversary by resort to perfidy. Acts inviting the confidence of an adversary to lead him to believe that he is entitled to, or is obliged to accord, protection under the rules of international law applicable in armed conflict, with intent to betray that confidence, shall constitute perfidy. The following acts are examples of perfidy: (a) the feigning of an intent to negotiate under a flag of truce or of a surrender; (b) the feigning of an incapacitation by wounds or sickness; (c) the feigning of civilian, non-combatant status; and (d) the feigning of protected status by the use of signs, emblems or uniforms of the United Nations or of neutral or other States not Parties to the conflict. (White flag suicide bombers in Iraq)
Protocol I, Art. 44., Sec. 3
In order to promote the protection of the civilian population from the effects of hostilities, combatants are obliged to distinguish themselves from the civilian population while they are engaged in an attack or in a military operation preparatory to an attack. Recognizing, however, that there are situations in armed conflicts where, owing to the nature of the hostilities an armed combatant cannot so distinguish himself, he shall retain his status as a combatant, provided that, in such situations, he carries his arms openly:
(a) during each military engagement, and (b) during such time as he is visible to the adversary while he is engaged in a military deployment preceding the launching of an attack in which he is to participate. (Hammas, Hezbollah, and AQI fighters drop their AKs and pretend to be civillians)
So, who are the war criminals again?