An Israeli soldier has been convicted of manslaughter for the killing of a British peace activist in the Gaza strip in 2003. Tom Hurndall was escorting children away from Israeli gunfire when he was shot in the head; he died nine months later, having never awoken from his coma.
This is a victory for justice and for the principle that even soldiers are accountable for their actions. But at the same time, it highlights the ongoing injustice faced by the Palestinian people. Tom Hurndall's killer was only prosecuted because his victim was British, and because his family and the British government pressed the Israeli government to investigate properly and enforce the law. By contrast, those who shoot unarmed Palestinians escape prosecution. As a consequence, the only justice available to the Palestinians is the lex talionis, "an eye for an eye", the "justice" of the suicide bomber. But that's not justice - it's just bloody, indiscriminate vengeance, and exactly what justice systems exist to prevent.
This is essentially Locke's formulation of the classic Hobbesean problem, and the answer is the same: justice. Israel must prosecute those of its soldiers who murder civilians, and do so in a fair and open manner whose impartiality cannot be questioned - because without justice, there can be no peace.