Seems straightforward:

Unlike other issues related to Israel’s conduct in its war against Hamas in Gaza, which has claimed more than 30,000 lives and displaced more than 85% of the population amid widespread destruction, the human-made famine occurring in the Palestinian territory appears more straightforward.

While the question of civilian casualties from specific attacks and from the wider policy of bombing will need to be tested against highly contested notions in international humanitarian law such as proportionality and necessity in conflict, the war crime of starvation is simply and clearly defined.

Underpinning the allegations is the fact that as a belligerent occupying power in Gaza, Israel is legally responsible under article 55 of the fourth Geneva convention for “ensuring the food and medical supplies of the population”, which requires the occupier to “bring in the necessary foodstuffs, medical stores and other articles if the resources of the occupied territory are inadequate”.