Weird War II is the Savage Worlds adaptation of Pinnacle's formerly d20-based Weird Wars setting. Not as in-depth as the original version, which was spread out over seven books which covered the various theatres. There have also been some tweaks, like removing the OSI adepts.

From the publisher:

Since the dawn of man, there has been war. And where there is war, there are dark things lurking in the shadows--feeding off the fear and terror of violence. But there are champions as well. Whether their secret societies are called the Twilight Legion or the Phoenix Command, the "Sons of Solomn" have fought against evil through the ages.