While organizers insist that the $6-million Dubai World Cup and other graded races at Nad al Sheba Racecourse will be held March 29 despite the possibility of a war between the U. S. and Iraq, the number of American horses that will participate in the program continues to decline.Over the weekend, trainer Darrell Vienna ruled out the Golden Shaheen on the World Cup card for Disturbingthepeace, Echo Eddie and/or Nuclear Debate. "One of them will go to Japan (for the Japan Cup Sprint on March 30)," Vienna said.Dubai-bound horses are scheduled to be flown out of California on Saturday while the U.S. deadline for Iraq to disarm is two days later.Meanwhile, World Cup committee chairman Les Benton has assured that the race will be held as scheduled."The Dubai World Cup will go ahead, there is absolutely no doubt," Benton said. "Recent reports are totally inaccurate and incorrect. All systems are go for March 29 and we are looking forward to staging the most successful Dubai World Cup to date. We are anticipating record number of overseas runners and the highest number of American entries for the event."Two of America's top stars, Medaglia d'Oro and Xtra Heat, are headed for the Dubai World Cup and the $2 million Dubai Golden Shaheen, respectively. Also possible for the World Cup are two of Europe's leading horses of 2002, Grandera and Sulamani. In Saturday's Maktoum Challenge Round III, Grandera was hard-pressed to defeat Grundlefoot, and it is possible he could run instead in the Dubai Duty Free, where he would face South African filly champion Ipi Tombe, winner of Saturday's Jebel Hatta.