 Complete the following phrase:  The main feud heading into the Royal Rumble was between the WWF World Heavyweight Champion The Ultimate Warrior, who had been champion since defeating Hulk Hogan at WrestleMania VI on April 1, 1990, and Sgt. Slaughter, who had returned to the WWF in 1990 and became a villainous heel sympathizer of the Iraqi government. Their feud began building during a time when the United States was engaged in 