This trade contains X-Men (2011) issues #20-23 and X-Men (1963) #14.
I haven't read much X-Men related comics since Whedon's run on Astonishing. War Machines caught my eye and featured an interesting group - the back cover text described Storm leading a team of "Utopia's most powerful mutants - Warpath, Psylocke, Colossus and Jubilee." Wait, Jubilee?! Ok, between comments like that and what I've heard about the recent Cyclops/Wolverine split obviously I'd missed a lot of changes. Since this trade also sounded like a good jumping on point I decided to give it a try.
The title "War Machines" plays double reference to the threat Storm's team faces, a nation locked in border disputes that has decided to solve the problem with an army of Sentinels, and the fact that they cross paths with NATO's enforcer, War Machine. While there's not much in the way of explanation of past developments to catch new readers like me up, important information on the developments themselves is quickly presented in the first issue. Colossus now houses the powers of the Juggernaut, Jubilee is a vampire, etc.
The issues here are what I generally refer to as "action fluff." There is an interesting set up and payoff to the situation that the X-Men are dealing with, and it's a decent storyline framework, but the focus is on X-Men vs Sentinels and taking Storm's new team out for a spin for the readers. And there's nothing wrong with that - I enjoyed War Machines for what it is. I just mention it because anyone looking for more depth to develop the titular characters or justify Marvel's annoying trend of collecting only 4 new issues at a time in trades won't really find it here.
The art is very good and has a dark tone that compliments the covert strike team concept nicely.
I'm really not a fan of early Marvel work, so while I understand the inclusion of the Sentinels first appearance I really would've rather the pages be used to reprint something else (from the Claremont era maybe, or better yet just more new issues).
War Machines is a fun little story that wasn't mind blowing but that I enjoyed and has me interested enough to check out more. While I suppose means mission accomplished, but it's somewhat non-essential and insubstantial and I'm not sure it supports a retail price trade purchase on it's own.