The twentieth century saw the unprecedented individualization, legalization, and criminalization of responsibility in international relations. At the start of the century, if any agent was held responsible in the international sphere for harm resulting from conflict or war, it was the state, and states were held politically (rather than legally, for the most part) responsible for their acts by other states. By the end of the century individuals were held legally (often criminally) responsible for such harm, now defined as “war crimes” or “atrocities.” Individuals were increasingly held responsible by international or hybrid tribunals set up under the auspices of the most powerful international institution in the post-1945 system, the UN Security Council, and with significant financial support from the world's most powerful states, foremost being the United States. Only a few years into the twenty-first century, trials of individuals were under way at an independent International Criminal Court (ICC). Our first reaction when we see news reports of war or civil conflict is frequently to ask which individuals are responsible and how they are to be punished.
"Excesses of Responsibility: The Limits of Law and the Possibilities of Politics".
https://www.cambridge.org/core/journals/ethics-and-international-affairs/article/excesses-of-responsibility-the-limits-of-law-and-the-possibilities-of-politics/A57A5011E1A88DF744D4E1C9BC5E8439 (2011-12-15).