Stuart Pemberton has been agitating against rearmament. In reality, he is a fifth columnist, supporting the invasion of Metropolis by "Nation X". Superman prevents enemy forces from bombing the city, poisoning the water supply, and destroying a bridge, then rescues Lois, who Pemberton is using as a hostage.
In the end, as usual, Clark has beaten Lois to the punch with a news story. I can't help but feel this is a little mean-spirited of him. It's true that Lois always ends up in serious danger, but she really is going out and finding stories, and he's just using his powers to get his stories in first--cheating, pretty much. And it's not so sneaky of him, either, somehow turning in stories that he, as Clark, should have no knowledge of.