New Frontier: How the Trinity were Formed
From the DC: New Frontier special released to coincide with the release of the movie.
Contains possible spoilers for the series, if you already haven't read it yet. And if that's the case, go! Go now and read it! Diana and Clark are asked to arrest Batman for him operating as a superhero, after the McCarthy hearings has lead to the US government declaring them to be illegal, with Diana and Supes being really the only two exceptions.
Diana refuses to arrest "an honorable man in the name of freedom and liberty" and walks off. Clark however, goes to see Ike to see if Eisenhower can explain why he should arrest a man they know to be a good man.
Cutting to Metropolis and Gotham,
After a lengthy and exciting fight scene, which I unfortunately had to cut to make the page limit, but just when Batman has enraged Superman almost to the point of squashing his head... Diana ex machina!
Diana's plan is that they stage a fight between Clark and Bruce in the middle of Gotham that ends in a draw and Bruce escaping. Clark doesn't really like the idea of lying about this, but he goes through with it in the spirit of their new friendship.