When Aidan O'Brien throws a saddle across three runners here at Meydan racecourse on Saturday night, it could draw a line under one of the more enduring disagreements in sport.
It is six years since O'Brien, who trains for John Magnier's Coolmore Stud syndicate, last ran one of his horses in Sheikh Mohammed's emirate. His absence, though no one concerned will ever confirm it, was evidence of the frost that descended on the relationship between the most powerful bloodstock operations in racing in the autumn of 2005.
It is one of the more puzzling sporting disagreements too, in part because, while rumours abound, few people beyond Magnier and Sheikh Mohammed themselves know for sure why the dispute arose, but also because it is bad for business. In their own ways, both Magnier and Sheikh Mohammed take a fiercely commercial approach to life – Dubai's skyline is testament to that – yet the Sheikh's refusal to buy Coolmore-bred yearlings at the bloodstock sales since September 2005 is a brake on the market that, in the end, drags at his own Darley Stud breeding operation as well.
But the appearance of Cape Blanco in Saturday's Dubai World Cup, the most valuable race of the season and one that Sheikh Mohammed conceived and developed, could signify that business links between Coolmore and Dubai are about to be revived. If so, it will be a victory for common sense, but a little of the credit too may belong to Dr Jim Hay, a recent recruit to the very short list of owners at O'Brien's Ballydoyle yard.
Hay, a Scot who now lives in Dubai, owns horses with his wife, Fitri, has been a significant new arrival in the bloodstock market in recent years, and recently bought significant shares in both Cape Blanco and Fame And Glory, O'Brien's 2010 Coronation Cup winner. Hay plays down suggestions that the couple have helped to bring a thaw between Magnier and the Sheikh – "don't overegg it", he said on Thursday – but he does acknowledge that the relationship has room for improvement. "It's no secret that there are strains between the folk in Ireland and the folk here," Hay said. "You could maybe see this [Cape Blanco's Dubai World Cup entry] as a move that could bring the two sides together.
"These squabbles are just part of life, they come, they go. I think hopefully in the years to come we'll see a lot more of the [Irish] folks with top-class horses here, which must be good for Dubai. It should be win, win, win."
Hay, who has a PhD in chemical engineering and worked for BP for 27 years, acquired Fosroc, a specialist chemical supplier, in 2002 and has been an owner for the best part of a decade. Buying into horses trained by O'Brien, though, is a significant new step.
"I first got involved with Coolmore by buying horses from them," Hay says. "Things are always changing rapidly, and opportunities that might not have existed 10 years ago can now appear.
"Anybody who is in any way associated with Coolmore can only see it as an enormous honour. I gave my wife Vincent O'Brien's biography the other day and told her in particular to read the section on the formation of the [Coolmore] syndicate with the Sangsters. There's a fantastic quote in there, Sangster went to see Lord Derby and said 'I know I'm going to be really serious for horses, tell me what I should do'. He told him two things. 'Firstly, find the best trainer you can find, secondly you have to start thinking one million at a time.' And that's where we are now.
"I've seen a few things saying that the reason they sold [Cape Blanco] to us was that they've gutted the horse and bottomed him out. If you go to Ballydoyle, Aidan has got this amazing collage on the wall of the 2001 season. Twenty-three Group One winners, you can't get your eyes off it. And if you actually look at it in detail, you'll find that a lot of these were older horses. He knows that he wants to do that again, only get 24, or 25. That's what drives him, and he can't do it unless he's got a few older horses."
The Hays have already invested millions in horseflesh, but this is not a wild splurge by a wealthy man with more money than sense. Purchases include around a dozen impeccably-bred fillies destined to form the basis of their own breeding operation, and every decision is carefully weighed.
"Racing for us is a serious business," Hay said. "We have a whole range of investments for our family group, which range from boring things like government gilts at one end all the way through to horse racing at the high-risk end. The returns are potentially huge, and unlike many other investments you can have fun at the same time.
"Everything we do will have a 15-year strategy, and we run our racing the same way. We will have a long-term strategy, and a five-year business plan to back it up. We have board meetings at which we discuss everything. It can be difficult for many of the board members to get their heads around. This is extremely high stakes but the returns on it are huge if it works."