Walgreens Boots Alliance Inc.’s (WBA’s) plan to acquire Rite Aid Corp. in its entirety is, for now, dead. For some, it was an inevitable conclusion to a strategy that was full of holes. For others, by far the majority, it was a surprising conclusion to a well-conceived plan to increase the already dynamic presence of the Walgreens brand in the U.S. and open new opportunities for retail and wholesale pharmacy globally.

The acquisition has been replaced by a planned WBA purchase of 2,186 Rite Aid stores in the eastern U.S., alongside other Walgreens-Rite Aid tie-ups that could influence purchasing at the two companies.

As for a bigger picture, that remains for WBA vice chairman and chief executive officer Stefano Pessina to know and others to ascertain. But this much is clear: WBA has become the most aggressive U.S. retailer to emerge in some time, along with Amazon, the online company that continues to stun the retail community, most recently by agreeing to acquire Whole Foods Market Inc. Apparently, a status quo doesn’t exist for Pessina, and the question he wrestles with is where he wants his company to be in five or 10 years — globally.

For the moment, it appears that WBA has bettered itself, surpassing CVS Pharmacy in store count in the American market. Rite Aid reemerges as a regional drug chain, confronting many of the issues that have challenged it for years. Initially, it appears that Rite Aid is still overmatched against Walgreens and CVS, though each faces its own challenges going forward. Foremost among these is the challenge of definition. WBA and CVS Health are no longer retailers, not, at least, in the way the concept was once defined. Each has emerged to epitomize a broader concept, though making that concept work remains a yet-to-be realized goal.

For the rest of the mass retailing community, business as usual remains the order of the day — at least for the present. Pharmacy remains a part of the business — but only a small part. Regional drug chains excluded, prescription drug sales constitute a small minority of the business, and there is little to indicate that that will change in the near term.

In all probability, the conclusion of WBA’s attempt to acquire Rite Aid is advantageous for the retailing community, giving it a sense of stability for the moment. Indeed, retailing of late in the U.S. has been anything but stable. In fact, it is changing more rapidly and unpredictably than has been the case since Walmart’s heyday as a market changer. Definitions, long fluid in terms of defining a retailer, are completely disintegrating, and yesterday’s drug chain is ­tomorrow’s …

So 2017 will likely be remembered as the first year of a new retailing generation, one in which ancient rivalries will be replaced by new forms of competition, and retail companies that once ignored each other will now, suddenly, have to acknowledge that they are competing for the same shopper.