The Phoenix War by F. R. Amthor
Two cadets discover an odd comet headed into the Solar System, and report it. Teams from the Chinese People’s Army Science Unit and the United Nations race to investigate. They learn that the comet is hollow. It contains alien DNA, which can be used to clone alien hybrids. As always with science, if it can be done, it will be done.
Meanwhile, back around the Oort Cloud, other aliens arrive, and settle the outer Solar System, preparing for war. Can the alien hybrids overcome them? And what will be the future of humanity?