Call of Duty Modern Warfare

Modern Warfare's campaign sees the return of a story mode in Call of Duty after last year's Black Ops 4 skipped offering one.
Though it's largely what you expect, there are some small changes, such as removing the tradition of finding optional collectables, to giving you a series of campaign rewards for multiplayer and Spec Ops modes.
Though the main story concludes, the Modern Warfare ending leaves the door open to more - which we can help explain some of the context behind.