The US suspended the gold standard to enter WWI. The US suspend bitcoin trading if it somehow did interfere with it's ability to make war.
No better way to validate it's usefulness than to ban it when you feel the pressure of competition.
But I think your argument is fundamentally incorrect. We had plenty of wars with gold backed currencies and we'd still have war if cryptocurrencies took over.
The US suspended the gold standard to enter WWI. The US suspend bitcoin trading if it somehow did interfere with it's ability to make war.