Something happened in the last week that has shaken our nation to its very core.

No, it’s nothing to do with the war in Iraq or the raise in the minimum wage ... or even Lindsay Lohan getting arrested again.

No, what has affected the confidence of America was the news that apparently a National Basketball Association referee has been fixing games.

Tim Donaghy, a 13-year veteran official, has just resigned in the wake of a federal probe. He’s accused of wagering on NBA games that he was working and providing inside information to others who were betting on games.

In short, if the allegations are true _ and there is little reason to believe otherwise _ Donaghy is a man with a gambling problem who was in deep with mobsters.

This incident has shaken the sports world like a James Bond martini. It will have to be determined if it is not only shaken, but stirred to action.

Basketball isn’t the most popular sport in America. Neither is baseball. For that matter, neither is football. The most popular sport in America is betting on football, both college and pro.

Brandon Lang, a prominent legal sports handicapper, recently told ESPN that on an average December day, about $50 million are bet _legally and illegally _ on sports events in this country.

If the crooks can get their clutches into someone such as Donaghy, who is estimated to make more than $200,000 per year, who knows how many baseball umpires, football refs or hockey officials are dirty.

Every bad call at home plate, every flag that nullifies a touchdown, every close decision between an offensive or defensive foul in the fourth quarter of an NBA playoff game will now make fans wonder if the call is legit.

NBA Commissioner David Stern hurried to put the best face on things Tuesday when he stressed that Donaghy is the only ref under investigation.

"We think we have here a rogue, isolated criminal here," Stern said at a media conference. "I feel betrayed by what happened on behalf of the sport. ... We take our obligation to our fans in this situation very, very seriously."

That’s a good thing, because Stern is well aware that if the NBA isn’t worth betting on, TV ratings will go down, shoe contracts will dry up and everybody involved will be making a lot less money.

The National Football League has its own problems, of course. One of its marquee players, Michael Vick of the Atlanta Falcons, has been accused of sanctioning torturing and killing dogs and being involved in the illegal dog-fighting industry.

Baseball continues to tie itself in knots over Barry Bonds’ alleged steroid use and perjury even as he closes in on the all-time home run record.

But Mr. Stern’s problem is so much more severe and needs to be addressed immediately and strongly. If it’s not, the shock waves will resonate all through the sports landscape.

You can certainly bet on that.