It a sequel to Iron Man (2008). After the events of The Avengers (2012) Tony has become a alcoholic and not taking the responsible of Iron Man seriously. Whilst he drunk he fired his race car driver and drove instead of him. Whiplash shows up during the race and attacks the drivers. So Happy drops off the suitcase suit. He uses it to stop Whiplash but makes a mess of it. So Rhodey talks to him about alcoholism and asks for a suit. Tony decides to stop drinking a make Rhodey a suit. He makes it and calls it War Machine. Because Rhodey military he uses to stop terrorists. Whiplash comes back and they team up. This is part of the Marvel Cinematic Universe (MHM15).