Errors and omissions are standard features of historical dramas everywhere. It is therefore no surprise to find Korean War history being filtered to suit domestic requirements in the three-hour Chinese blockbuster “The Battle at Lake Changjin.” Nor is it unexpected for U.S. military characters to be cardboard cutouts with excruciatingly bad dialogue. And, like many other jingoistic war epics, this prestige production co-directed by industry heavyweights Chen Kaige, Tsui Hark and Dante Lam

The latest in a long line of strongly nationalistic films released during the 100th anniversary of the Chinese Communist Party, “The Battle at Lake Changjin” has collected almost all its $905 million revenue (as of Dec. 27) from domestic ticket sales. It is currently the highest grossing film of 2021, with only “Spider-Man: No Way Out” and “No Time to Die” as serious rivals for the top spot.

This very old-fashioned production depicts a string of military engagements during...