Financial markets are deep and liquid, but still second fiddle for now, though US regulations are whittling that advantage away.

Dominant agriculturally. The Euro is not dominant, but still strong enough. Still second fiddle though.

Military, this is the laugher. Story over.

The network effects are also key. Who wants to trade out of dollars to hold the euro? They are not accepted anywhere. You don’t have to exchange dollars, people just take them in much of the world. That is not true of the dollar. More importantly it will take decades for the Euro to be trusted as a unified currency. it is a common discussion if the euro will survive or at least have several countries withdraw. Nobody seriously talks about US states pulling out of the dollar in favor of their own currency. Even if it stays together, it does not represent a unitary state. Instead it represents a fractious bunch of states. Would you trust the Euro zone to back up any promises long term? Even if they had a military worth speaking of could it be relied on to be gathered to act in a unified manner?

Given all that, why change? It can’t be because the Euro zone is more fiscally responsible, they aren’t. At this point at most I can see a case for some diversification, which I expect to occur. That is no disaster and would probably result in a more stable financial system.

One thing that I’m unsure about, however, is why gold or even the Euro, isn’t a threat to the Dollar’s supremacy, if not now, in the near future. Your analysis regarding the dominance of the country issuing the currency surely doesn’t affect a gold standard, does it? And the Euro meets nearly all those criteria, certainly enough to be used as a backing currency, doesn’t it?