When asked about the Korean War, most Americans don’t know much about it. This is in spite of the tremendous toll of the war and the extent of war crimes on both sides. Little attention has been paid in the West to the bombing of dams and other water infrastructure by UN forces in the Korean War. This is despite the fact that these bombing campaigns were arguably illegal under international law at the time, and certainly are illegal under international law today. The perpetrators were aware of the way that the attacks would be perceived, and went to great lengths to justify the attacks and obfuscate their true goal of collective punishment. Using both primary and secondary sources, I will argue that the UN bombing of hydroelectric dams in the Korean War constitute war crimes in hindsight while the UN bombing of irrigation dams constitute war crimes both in hindsight and at the time of the Korean War. I will illustrate that those in charge would not have tolerated the use of the same tactics by the adversary. While the technical legality and the strategic legitimacy of water infrastructure as a target in war can be debated, the nature of the attacks as acts of collective punishment must nonetheless be reckoned with today. This paper will seek to, as the introduction to Professor Cumings’ The Korean War puts it, “uncover truths that most Americans do not know and perhaps don’t want to know” about the Korean War. Americans must confront the truth about our war crimes if we are ever to be able to build a public understanding of our history that spurs us to deconstruct the military-industrial complex and make amends for our past imperial aggressions.