When it comes to women's basketball at the Olympics, it's the U.S. and everybody else. In case the 56-game winning streak and seven straight gold medals didn't communicate that clearly enough, Team USA's 26-point win over defending silver medalist Japan on Monday certainly did. 

Still, while the U.S. remains the gold standard, the rest of the world is only getting better. Plenty of challenges remain in Paris, and if the Americans don't bring their A-game, they could very well get beat. 

Who might be best positioned to knock them off? The most likely answer is "no one," but with one round of group play officially in the books, let's take a look at which teams stood out the most over the last few days.

France

Let's start with the big one. France and the U.S. don't share a group, but if they square off in the knockout rounds, it could be an absolute war.

French wing (and U.S. dual national) Gabby Williams has a credible claim to being the best player in the tournament who isn't playing for Team USA, and she's surrounded by a ton of intriguing young talent. France's skill, length and athleticism were on full display in a rout of Canada to kick off Group B, and Les Bleus likely stand the best chance of being able to match up with the Americans physically. Add in what would be a raucous home environment in a semifinal or gold medal game, and things could get dicey.

Germany

Most had Belgium pegged as the team in the U.S. group that could give it the most trouble. But Germany had its way with the Belgians in its opener: Belgium star Emma Meesseman got hers, but her teammates didn't meet her nearly halfway, seeming totally overwhelmed by Germany's defensive intensity. Again, there's a baseline of size and athleticism you need to have a shot of upsetting Team USA, and Germany would seem to clear it. It's unclear if the Germans have enough playmaking, but they're virtual locks to advance out of the group after dispatching Belgium, and sisters Satou and Nyara Sabally are a problem.

Belgium

Belgium's path is tricky after falling flat against Germany. But this team won gold at EuroBasket just a year ago, and if Williams isn't the best non-U.S. player in Paris, Meesseman is. The Belgians could be fighting for their lives in a final group stage match against Team USA, and that makes them very dangerous. Don't write them off just yet.

Nigeria

Hey, why not? Nigeria pulled off the most surprising result of the first round of group play, ambushing Australia with a harassing full-court press and some big-time 3-point shooting. Will that style work as well against the Americans? Probably not. But this team is totally fearless, and the U.S. does have a tendency to play with its food at times — a quality that Nigeria could be suited to exploit after forcing 26 turnovers from the Aussies.