What is a war crime, and who gets held accountable? Here's what you need to know

The ongoing conflict between Israel and Hamas has led to accusations of war crimes on both sides, after Israeli civilians were targeted in Hamas' Oct. 7 attack and Israel responded with airstrikes on the densely populated Gaza Strip.

Under these conditions, protecting civilians can prove difficult or impossible. But combatants are bound by international humanitarian law to minimize the impact on populations.

Here's what to know.

In war, what are the obligations of nations, their soldiers and groups such as Hamas?

Although the history of international law regulating warfare goes back to the first Geneva Convention of 1864, World War II — in which twice as many civilians as fighters were among the tens of millions killed and the Nuremberg Trials that held Nazi leaders to account for atrocities — spawned interest in expanding the scope of the agreement.

The 1949 Geneva Convention established, delineated combatants from noncombatants and set down the obligations of governments and militaries on how to minimize casualties and the suffering of civilians in wartime.