Who could have foretold just six weeks ago, when Walmart convened its shareholders’ meeting — that annual rite of spring designed to celebrate the past, predict a future of unlimited possibilities, and recognize the accomplishments of its vast network of stores and people — that the event would pre­sage the biggest management upheaval since Sam Walton announced, some 30 years ago, that Jack Shewmaker and David Glass would switch jobs and responsibilities?

Who could have foretold just six weeks ago, when Walmart convened its shareholders’ meeting — that annual rite of spring designed to celebrate the past, predict a future of unlimited possibilities, and recognize the accomplishments of its vast network of stores and people — that the event would pre­sage the biggest management upheaval since Sam Walton announced, some 30 years ago, that Jack Shewmaker and David Glass would switch jobs and responsibilities?

Who could have imagined that, less than two months after an event dedicated to the proposition that all is as it should be, the retailer’s U.S. CEO and senior merchant have moved on, a relatively new face has emerged at the head of U.S. operations, and the chief merchant’s job is one that remains to be filled? Can anyone doubt that further changes are in the wind, many of them promising to be of a dramatic, game-changing nature?

Yet the seeds of change were in the air on that Friday in early June, for those with the foresight, insight and sense of foreboding to recognize them. Those special few, many of them former Walmart associates, recognized, even as the meeting unfolded, that all was not well in Bentonville. Still, on the surface all appeared normal as the world’s largest corporation held its 2010 Annual Shareholders Meeting at the Bud Walton arena in Fayetteville, Ark., a location that has long been the venue of choice for this signature gathering. Some 17,000 people descended on Fayetteville for the occasion, the great majority of them Walmart associates.

If the associate attendance in Fayetteville numbered about the same as in previous years, the composition of that attendance was dramatically different, mirroring the retailer’s increasingly impressive global reach and presence. For Walmart has truly become a global company, the first in the annals of retailing. Not that the retailer operates in every corner of the globe. Rather, it has a meaningful presence in more significant parts of the world than any retailer could previously claim.

So it was that associates arrived from such South American outposts as Chile, Argentina and Brazil, from such Latin American locations as Mexico and Honduras, from Puerto Rico, China, Japan, Canada, the United Kingdom and all manner of places between.

The formats represented were as prevalent as the countries, perhaps a dozen permutations in all, ranging from bodegas, warehouse clubs and neighborhood markets to superstores, discount and hard discount stores.

Every store in the 15-country, 8,474-store retailer’s arsenal was authorized to send one representative to Fayetteville. And come they did — many making their first trip to America — to celebrate, mingle, renew old friendships and make new ones, tell tales, soak up the culture, and share the moment, with one another and the company that employs them. As well, they came seeking what they had always found: Unmitigated good news.

On this day, however, they were destined to be disappointed.

Though much of the youthful exuberance that marked the company in its formative years remained, the 2010 Annual Meeting made clear that the retailer that Sam Walton conceived and launched 48 years ago has changed. It has matured and, approaching middle age, it has grown up. And with middle age has come the growing pains that inevitably challenge middle-aged companies.

One inevitable result of Walmart’s approaching middle age was an absence of the stunning announcements, record-setting performance figures and epic predictions that once routinely anchored the retailer’s annual meetings. Breathtaking news, at least domestically, has been more elusive of late.

Still, a guest at the Annual Meeting was easily transported back to the retailer’s halcyon years, enveloped and mesmerized by the circus atmosphere that has traditionally punctuated this event: the hoopla, music, cheers, songs, headline entertainers, deafening noise and self-congratulatory speeches that have long since become second nature to the world’s largest retailer.

Most of the hard news, however, turned on the stunning success of Walmart’s international operations, that $100 billion unit that now accounts for some 25% of the company’s sales and, in the bargain, has come to do more business than any other United States retailer has ever recorded. So it was that a visitor to the Annual Meeting heard about the launch of operations in India and the probability of Walmart’s entering Russia in the near future, possibly via an acquisition. But the retailer made clear that it was pleased with the glistening performance of virtually all of its foreign outposts.

Domestically, the story was not as upbeat, however. Clearly, in recounting U.S. performance, the retailer was largely going through the motions. As well, a cultural shift was in the air, evident to those with the history and the perspicacity to recognize it. It was evident in the fact that the retailer’s suppliers, once valued as one of the pillars of Walmart’s success, were largely ignored in Fayetteville, a presence to be tolerated and endured but neither recognized nor appreciated.

Then too, Walmart’s senior managers, many of them relatively new to the corporation (among them those who have since departed the company), were clearly uncertain as to how to treat the many former Walmart associates who showed up at the meeting. As a result, these valuable contributors to the company’s history, success, legend and legacy were largely ignored, an oversight Sam Walton would never have countenanced.

Still, the 2010 Shareholders Meeting was, on one level, a stunning display of the reach, power and strength of the company that Sam Walton founded 48 years ago with a single discount store in Rogers, Ark. However, on a more meaningful level, it became increasingly clear on that Friday in Fayetteville that the halcyon days of stunning domestic accomplishment and unlimited domestic aspirations have come to an end ­— at least for now. Domestically, Walmart is no longer America’s most exciting or explosive retailer.

And though it has emerged as the world’s dominant retailer, an impressive, indeed mind-boggling achievement, it has clearly lost focus and momentum at home along with the distinctive cultural roots that drove, indeed anchored, the retailer’s achievements.

Thus, the management changes that came in the meeting’s aftermath are clearly an attempt to rediscover that focus, regain the momentum, reenergize that uniquely Walmart culture and reconnect with a supplier community the retailer had largely forgotten — one the new leadership is already reaching out to, to the relief and delight of Walmart’s key suppliers — with the goal of returning America’s largest retailer to the position it so long and so successfully occupied: The U.S. retailer that, more than any other, succeeded by understanding who its customer is and what that customer wants.