Peter Cetera's "Glory of Love" was the hit theme song from The Karate Kid Part II, but it was originally meant for and was rejected from the Rocky IV soundtrack before the Karate Kid sequel picked it up. Released in the summer of 1986, The Karate Kid Part II continued the story of Daniel LaRusso (Ralph Macchio), who accompanied his sensei, Mr. Miyagi (Noriyuki "Pat" Morita), to his ancestral home of Okinawa, where they found old grudges and new enemies.
Rocky IV hit theaters in November 1985 and the Sylvester Stallone boxing flick featured his Philadelphia-born champion, Rocky Balboa, going up against a Russian threat named Ivan Drago (Dolph Lundgren). Rocky IV is the most straightforward and cartoonish of the Rocky films but it remains beloved because of its black-and-white, USA vs. USSR politics where Rocky's win over Drago seemed to provide an answer to the Cold War. Rocky IV also has a memorable soundtrack, with James Brown's "Living in America", Survivor's "Burning Heart", and especially John Caffery's "Hearts on Fire" providing a rousing anthem during Balboa's training sessions as he prepared to fight the towering Russian.
However, United Artists and Sylvester Stallone opted not to pick up Peter Cetera's "Glory of Love", which the former Chicago band member wrote and composed as the end-credits song for Rocky IV. An outright love ballad, "Glory of Love" didn't suit Rocky IV's uplifting ending where Rocky triumphed over Drago against all odds. Instead, Stallone reprised "Hearts on Fire" to send pumped-up audiences home as the closing credits began. But Rocky IV's loss was The Karate Kid Part II's gain, and its producers snatched up "Glory of Love" as the main theme song for the sequel to the hit 1984 film, The Karate Kid.
The Karate Kid Part II's producers made a wise decision: the sequel was a hit during the summer of '86 and, fueled by the film's success, "Glory of Love" reached number one on the Billboard Hot 100 and remained at the top spot for two weeks in August. The power ballad received Academy Award and Golden Globe nominations for Best Original Song, and "Glory of Love" was also nominated for a 1987 Grammy for Best Pop Vocal Performance by a Male Artist. Despite James Brown and Survivor's hit singles, "Glory of Love" did far better at the pop charts, and in the major award shows, than the music on the Rocky IV soundtrack.
Ironically, "Glory of Love" doesn't quite fit with The Karate Kid Part II either, although the syrupy love song is indeed more suited to teenage Daniel's summer infatuation with Kumiko (Tamlyn Tomita) than it would have been in Rocky IV, wherein Rocky's ongoing love story with his wife Adrian (Talia Shire) received only cursory attention. Still, the lyrics of "Glory of Love" describe its hero as a "knight in shining armor from a long time ago" who is the "hero" the girl has "been dreaming of"; even though Daniel had a violent climactic showdown with Chozen (Yuji Okumoto) to "fight for [Kumiko's] honor", it's still a bit of a fanciful stretch to depict Daniel and Kumiko as the epic romance the song describes.
All in all, "Glory of Love" was the latest aspect The Karate Kid series borrowed from Rocky. The martial arts saga followed the successful Rocky blueprint almost to the T, from the hero having a wise old mentor to the exciting training montages, to the hero winning and the films ending on emotional highs for audiences. The Karate Kid trilogy was also directed by John G. Avildsen, who won the Oscar for Best Director for directing the original Rocky, and Bill Conti composed the unforgettable music for both Rocky and The Karate Kid. "Glory of Love" may not have been right for Rocky IV, but time has proven the bombastic ballad to be arguably the most enduring part of The Karate Kid Part II.