There was never such a time when they didn't care that an alternative appeared to their biggest superpower.
American Senator Schumer was on their TV talking about Bitcoin powering Silk Road practically as soon as it appeared. That was what, a year or two after Bitcoin began?
Their position was from the beginning that if they can't destroy it, they will work to loot it through direct and indirect #taxes and controlling as much of Bitcoin infrastructure and exchanges as they could to coopt the Bitcoin ideology and purpose, and pilfer its users.
They succeeded; Tether fiatcoin is used far more than Bitcoin as the "digital cash" Bitcoin was intended to be!
What's left for them to do is to become the biggest Bitcoin holders by "nationalising" for "national security" the giant Bitcoin repositories they control, such as Conbase, et cetera.