Which division opponent poses the biggest threat?

It was announced this afternoon that Bryce Harper was named as the Nationals' team winner of the 2012 Heart and Hustle Award, given out by the Major League Baseball Players Alumni Association. The award honors active players who demonstrate a passion for the game and best embody the values, spirit and tradition of the game of baseball. What a shocker - Harper winning an award for demonstrating passion and hustle. If there was ever was an award that screamed out "Bryce Harper," it's this one. The league-wide winner of the award will be announced November 13. Meanwhile, here's how the National League East shapes up right now, as we get set to kick off the second half of the season tomorrow: Nationals - 49-34 Braves - 46-39 (4.0 games back) Mets - 46-40 (4.5 games back) Marlins - 41-44 (9.0 games back) Phillies - 37-50 (14.0 games back) Like the Nats, the Braves, Mets and Marlins all went into the All-Star break having won six of their last 10 games. The Phillies, in full-on tailspin mode, lost nine of 10 going into the break. While the Nationals pace the NL East and rank second in the National League in run differential at plus-58, both the Braves (plus-34) and Mets (plus-20) showed well in the first half in an important statistical category. The Marlins, frankly, are lucky to be just three games under .500 given their minus-56 run differential, while the Phillies are at a minus-28 at the break. I think we can all agree that the Phillies can pretty much be ruled out at this point. At 13 games under .500 and 16 games back of the Nats in the loss column, their playoff hopes are essentially gone with 75 games left to play. The Marlins have plenty of talent and could certainly catch fire and make things interesting over the season's last few months. That's not impossible. But it is unlikely, especially given the combustibility of that group and all the off-field issues going on down there. That pretty much leaves the Mets and Braves. Both teams don't really do anything exceptionally well. They both rank in the middle of the pack in most offensive categories and sit right next to each other in team ERA, as well. Atlanta's staff ranks 14th in the league with a 3.91 ERA, while the Mets are right behind at 3.96. The Mets score 4.58 runs per game; the Braves score 4.6. If I had to pick one team which I felt was the bigger threat to the Nationals, I'd pick the Mets, just because of the 1-2 at the top of their rotation in R.A. Dickey and Johan Santana. If those two continue to pitch the way they have so far this season, the Mets will stay in the mix for a playoff spot. If health isn't a factor, though, the Braves might be the more well-rounded team. But barring a shift, I don't really see any of the Nationals' division rivals having enough to come back in the second half and take home the division title. Neither the Braves nor the Mets jump out as scary teams that can dominate over an extended stretch, and the Marlins might have dug themselves too deep a hole. Which team within the NL East do you think poses the biggest threat to the Nats as they embark on the playoff push?