If bitcoin ever got large enough to be perceived as a threat to USD (which is a long ways off) the bitcoin community would not have the resources to take on the US gov. Being geographically spread out is irrelevant. For a small fraction of one of its many defense institutions annual budgets the US gov could easily build an ASIC cluster larger than the entire bitcoin mining network. They could even just start maliciously buying/selling large quantities of btc to keep the btc market volatile. To put it into perspective: btc current total market cap is ~4billion, and the NSAs annual budget is ~12billion.
Bittorrent is used to download fucking movies while a lot of serious people invest millions in Bitcoin. Federal armies will have to deal with a lot of vested interested. In addition, some bankers and regulators may look seriously into Bitcoin and realize how good it is for storing their own bribes and bonuses and thus buy it. Then "fight" against it only to confiscate for themselves even more.
By the time anyone would seriously decide to throw billions to fight anonymous miners and billion of smartphones, Bitcoin monetary base will be a trillion USD and hashrate will be boosted by Chinese government protecting and taxing their miners.
Also, it's one thing to say that some company helped Osama bin Laden to launder his money - there will be evidence and no one would make a big story out of it. Another thing is to say that "we cannot do anything about this protocol, so we will shut down every single company just because they might use it". To shut down tens of companies you'd need to show evidence that they all somehow launder tons of money. That would be an epic event and it will be well-advertised, so prosecutors would have to be even more careful in what they say, or they will look like simple bullies on every newspaper. It's just entirely different scale of action to take on everyone connected with Bitcoin.
If they do things slowly and try to kill companies one by one, then each time they would create more clarity on how to be compliant with the law which will make every next case even more difficult.
I have no doubt there will be war (there's one already with all this regulatory crap, seizure of funds etc.), but it sure won't be one single decision and little attention, like in case of Egold.