I would dispute that Bitcoin is likely to ever pose a threat to the US 'currency hegemony', at least as a currency in its own right rather than a glorified paym

I would dispute that Bitcoin is likely to ever pose a threat to the US 'currency hegemony', at least as a currency in its own right rather than a glorified payment network with prices usually delimited in… US dollars. More practically, I would dispute that the US regulators' concern about Bitcoin has much to do with speculation on its potential to pose such a threat in the future, as opposed to its current suitability for tax evasion and popularity for money laundering, crime, etc. (Please note that I'm not claiming Bitcoin is only or primarily used for those things, only that people who want to do those things often use Bitcoin.) *edited to add tax evasion, which is of course the stated purpose in this instance...