While the DoJ's often-obnoxious international behavior gets plenty of attention, the "how much does this matter to the US?" threshold for them to get involved rises sharply beyond the US border. And the legal basis for their involvement (Boeing does have lawyers, to argue the details in court) often changes, too.
OR - if a small-time, local crook is robbing US banks, how likely is the DoJ to get involved? (Hint: Answer includes "FBI".) Vs. how many small-time, local bank robbers is the DoJ chasing in Canada? Poland? Thailand?