Seeing as archival research is impossible for the foreseeable future, here's a tip for folks interested in the Korean War: thanks to an agreement w/ NARA, the Nat. Archives of Korea has digitized a HUGE collection of US docs.

https://nl.go.kr/NL/contents/N20402000000.do

Allow me to curate a bit:

For those wanting to know more about the targeting and destruction of NK cities during the war, you can find Air Force mission reports and target charts here:

https://nl.go.kr/NL/contents/search.do?detailSearch=true&seriesName=Office+of+the+Director+of+Intelligence+Reconnaissance+Branch+Korea+1950-1953&systemType=%EC%98%A8%EB%9D%BC%EC%9D%B8%EC%9E%90%EB%A3%8C&category=%ED%95%B4%EC%99%B8%ED%95%9C%EA%B5%AD%EA%B4%80%EB%A0%A8%EA%B8%B0%EB%A1%9D%EB%AC%BC&pageSize=30&pageNum=1#viewKey=CNTS-00053796676&viewType=C&category=%ED%95%B4%EC%99%B8%ED%95%9C%EA%B5%AD%EA%B4%80%EB%A0%A8%EA%B8%B0%EB%A1%9D%EB%AC%BC&pageIdx=7

For those interested in war crimes and the treatment of POWs you can find transcripts of trials presided over by the US Judge Advocate General here:

https://nl.go.kr/NL/contents/search.do?detailSearch=true&seriesName=International+Affairs+Division%3B+War+Crimes+Branch%3B+Investigation+of+Atrocities+Against+POW%27s+in+Korea%2C+1952-54+I&systemType=%EC%98%A8%EB%9D%BC%EC%9D%B8%EC%9E%90%EB%A3%8C&category=%ED%95%B4%EC%99%B8%ED%95%9C%EA%B5%AD%EA%B4%80%EB%A0%A8%EA%B8%B0%EB%A1%9D%EB%AC%BC&pageSize=30&pageNum=1#viewKey=CNTS-00053797789&viewType=C&category=%ED%95%B4%EC%99%B8%ED%95%9C%EA%B5%AD%EA%B4%80%EB%A0%A8%EA%B8%B0%EB%A1%9D%EB%AC%BC&pageIdx=4

Interested in the day-to-day experience of soldiers? The records of the Quartermaster General include some grizzly and sometimes colorful detail (such as this letter to a jam company from a soldier dissatisfied w his C-ration):

https://nl.go.kr/NL/contents/search.do?detailSearch=true&seriesName=Food+and+Container+Institute.+R%26D+Project+Case+Files+%28Development+of+Combat+Rations+WW+II+%26+Korea%29&systemType=%EC%98%A8%EB%9D%BC%EC%9D%B8%EC%9E%90%EB%A3%8C&category=%ED%95%B4%EC%99%B8%ED%95%9C%EA%B5%AD%EA%B4%80%EB%A0%A8%EA%B8%B0%EB%A1%9D%EB%AC%BC&pageSize=30&pageNum=1

Korean-language readers can access some incredible material in the vast collection of "Captured North Korean Documents." Historiographically speaking, this collection has had an outsized influence on Eng. language scholarship on NK.

https://nl.go.kr/NL/contents/search.do?detailSearch=true&seriesName=Captured+Korean+Documents%2C+Doc.+No.+SA+2009+II&systemType=%EC%98%A8%EB%9D%BC%EC%9D%B8%EC%9E%90%EB%A3%8C&category=%ED%95%B4%EC%99%B8%ED%95%9C%EA%B5%AD%EA%B4%80%EB%A0%A8%EA%B8%B0%EB%A1%9D%EB%AC%BC&pageSize=30&pageNum=1

Medical experiment data. Chemical Warfare Service memos. US State Dept. cables from Seoul. It's all there, accessible through your laptop. Poke around!

Feel free to shoot me a line if you have trouble navigating the K. language interface. I'm happy to help.