I am wondering if it would be acceptable to re-organize this page in the following way:
At the start of the article, a working definition of types of atrocities can be provided, for example basic definitions of genocide, war crimes, crimes against humanity, etc. (I will put my suggestion at the end of this post).
Then, instead of the main headings being types of atrocities, instead the headings can be world regions, such as continents, and subheadings can narrow it down to countries, regions, and specific events and people groups and atrocities that happened to them.
This way, I think the full breadth of atrocities that have been done to a certain region or group can be seen in their historical context, and the continuity of the US impact on a region or people can be seen. I think separating each section by "atrocity type" creates a broken continuity that removes the atrocity from their context, reducing them to mere statistics that do not explain the issue dialectically. It also causes the editor/writer to have to personally make the call themselves whether to specifically define something as an act of genocide or not, a war crime or not, etc. or have to split up a complex event that entails multiple types of atrocities into different sections.
Defining atrocities at the top of the article with a sufficient caveat explaining that atrocity is a difficult thing to define will then put it on the reader to use their own judgement in defining what happened to each region and people group when atrocities were committed there by the US, which I think is a more solid way to may progress on this article, as the editors of the article won't have to be determining which kind of atrocity was committed but can simply record all atrocities by region. (Edit: But they would also be free to describe/classify the atrocity in that section if they did see fit to do so).
I think this will allow progress on this article to occur more quickly. After more information is added, then perhaps there will be enough material that there can be sections in the end that categorize the atrocities in other ways, such as "by targeted group", "by atrocity type", "by time period", "by world event", etc. (depending on how the article initially develops, it will become more clear what kind of categories would be useful).
Example paragraph on "types of atrocities" that could begin the article:
"What constitutes an atrocity does not have a universally accepted definition. However, a framework used by the United Nations describes atrocity crimes as a violation of international criminal law that falls under the historically three legally defined international crimes of genocide, war crimes, and crimes against humanity. Crimes against humanity are certain acts that are purposefully committed by a state, or on behalf of a state, as part of a widespread or systematic policy, typically directed against civilians, in times of war or peace. Ethnic cleansing is considered by many to constitute an atrocity crime. Mass killing is a concept which has been proposed by genocide scholars who wish to define incidents of non-combat killing which are perpetrated by a government or a state. There is little consensus on how to officially and universally define such acts, and in many cases there can be overlap in the conditions and contexts where such acts occur, making it possible to classify them in multiple ways. Therefore a broad term such as 'atrocity' may be used to describe a wide variety of acts which, when examined individually, may be described with more precision in their proper context."