It just goes on and on.......
It's a silly film and should have been a bit of fun, but takes itself far too seriously. Tom does lots of pensive emotional gazing (not very well) and it just kills the pacing. They could easily have cut an hour or of it and returned it so a pacy, fun romp like the earlier MI films, but it wants to be more than that.
If you want to be serious, you can't get away with (among other sillyness) the utter nonsense of swimming or off a nuclear sub in freezing water in your undies to be rescued from under the polar ice cap by your girlfriend in her undies, then recovering in an inflatable hyperbaric chamber on the ice.
In serious films you would be dead. Much like my feeling for this film.