Quite enjoyable movie, intriguing story and The Rock plays the role well as he is desperately trying to keep it all from falling apart.
I felt the backstory with the son in prison was a bit thinly developed and didn't come across as important as it was. I mean it made a regular working Joe go apeshit bananas and directly go after an international drug kingpin. You wouldn't go that far if it wasn't life-or-death important, and frankly the son in jail was crucial to the whole movie.
Guess what I'm saying there should have been more angst, more in-your-face frantic helplessness - more drama :)
Maybe they didn't think Dwayne could pull it off. So he isn't one of the century's finest actors, but he has a consistent level of solid performance in him. Always look forward to seeing him in movies. I agree with CSSCHNEIDER below, he deserves better.
It's not your typical high-octane-kick-ass-one-man-army-vengeance thriller, that's been done to death for decades and those mainly exist to make the lead actor money. This one is a bit more delicate. Shit still hits the fan in the end so it's not without action.
Just realize it is what it is and enjoy it.