@Jonas22:
Also, remember that no matter how powerful you perceive Whitebeard or Shanks to be, right now they are in check and have been for the better part of 10 years (20 if you count Whitebeard). The Strawhats are the free radicals in the system; they're the ones worth stopping, because they could tilt the scales and "ruin everything" (from the viewpoint of the gorosei).
And!
@Ivotas:
The point that the World Government (that has the power of the entire Marine, the Cipher Pols and even from the Shichibukai at their hands) consider a cooperation between Whitebeard and Shanks very problematic does indeed mean to me that they can´t be handled by such a thing as a Buster Call. There must be a reason why such guys who can be a huge problem to the WG are still left untouched and I believe that it is because these great pirates could cause serious damage to the WG. Just look at what the Strawhats can do to Enies Lobby. I don´t want to know what the Whitebeard and Red Hair Pirates capable of doing to the WG.
I'm not sure if my source is correct, but:
Whitebeard has a special contract or agreement with the World Government (much like the Shichibukai), that renders him immune from hassle.
The World Government generally seems very willing to align with the most powerful pirates (not only in Whitebeard's case, but also look at the Shichibukai) in hopes they'll exert their power of influence over more radical pirates. Similarily, in Enies Lobby, they use pirates and criminals against one another in their judgement/punishment, as seen in Enies Lobby.
And Luffy is very much a radical; he's so random, it's hard for anyone, including the readers, to predict what he's going to do. After 10/20 years, the World Government knows what to expect from more "stable" pirates like Whitebeard and Shanks, but Luffy's only been in the World Government's sight for a short while, and his randomness makes his actions difficult to predict.
@Jonas22:
Things don't always scale linearly. I'm pretty sure that it took a much more awesome power to kill everyone at Ohara than the power which Arlong wields. Not only that, but I think the jury is still out as to what exactly a Buster Call is. There might be reasons to avoid using it when not completely necessary.
Well-said! I believe that there's more to the brute strength of the Buster Call than a fleet of marine ships, and this will justify not only Robin's panic regarding it, but also the Marines' reluctance to use such a weapon.
Let's use the atomic weapon parallel again. Hoover used the atom bomb to end the war as quickly as possible. Not only did the bomb kill thousands upon thousands of people–soldier and civilian alike, but it also spread radioactivity over the area. I'm sure that using a weapon such as the Buster Call has long-term reprecussions, just as the atom bomb did.
@Jonas22:
Anpther important thing that you are ignoring in your diagnosis, Ivotas, is that Robin is not Nami. Robin isn't some teenage girl with a gift for map making that stole from small time pirates in the weakest sea in the world. Robin is a genius historian who passed the test to become an archaeologist with perfect marks at age 8. She's been on the run for 20 years, aligning herself with people at least as powerful as one of the Shichibukai (we don't know the others, but perhaps some even more powerful). Her knowledge of history would help her understand the scale of this situation better than anyone else. She has shown herself to be mostly rational, her actions ruled by logic and not emotion.
Exactly what I was trying to say; Arlong ruled over the West Blue, so he made sure that he was the strongest in the area. Arlong was all that Nami knew. Robin had 20 years to cross from West Blue and into the Grand Line, meeting a variety of different people with different strengths and different powers–and yet she still believes that the Buster Call is more powerful.
As you said, Robin's logic can be completely defined by history. People study history to learn from it, and to avoid making the same past mistakes. The same is in the case of Robin. She has seen what the Buster Call can do, and rather than allow it to destroy everything she cares about again, she's willing to sacrafice.
Furthermore, as you said, Robin is for the most part, very in control of her emotions. The one instance when she isn't is during the encounter with Aokiji, and she managed to keep her emotions in check for a good amount of time before attacking him. There's likely a good reason why she attacked him, and I'm sure that we'll see this in the coming chapters.
@Ivotas:
Well the only difference is the size but not the general topic itself. Nami lost only one person and she had 8 years to meet even more powerful people in East Blue. Smoker for instance is one, but she never found him in her 8 years.
Robin lost much more people with a much more destructive force and spent 20 years in the underground. It is the same thing just much bigger. What East Blue´s Smoker is be to Arlong, could actually the Whitebeard Pirates be to the Buster Call.
In other words losing Everyone at Ohara is more then losing just Bellemere. Buster Call is a bigger powerthen Arlong. 20 years is more then 8. The Grand Line is a much more difficult place to explore then East Blue. And Whitebeard (for instance) is stronger then Smoker.
I see it as the completely same problem, just with a difference in size. But the general tenor is that Robin, just as Nami before her won´t believe that her horror can be surpassed until she witnesses it with her own eyes.
You've got a good point here, but you're missing one key point: Robin won´t believe that her horror can be surpassed until she witnesses it with her own eyes. She's had 20 years in the Grand Line to find something even more powerful than the Buster Call, and she hasn't. I think people are underestimating the power of the Buster Call, or truly believe that the Straw Hats will win again as they always have, because they're so used to the "hero always wins" convention. Just as Jonas22 said, I'd like to see these conventions broken, because if anyone can do it, it's Oda.
Wow, I think I covered everything. Sorry about the long post, and sorry if I missed anything. x_x