> If (and it is, admittedly, a big assumption) we assume that USD and EUR are broadly stable currencies over the long term

Yeah, er, that's a very big if. There's no real reason to assume that, and history doesn't really bear it out.

If anything in the near term you'd probably expect the USD to weaken further vs the Euro; Trump seems _very_ keen to install a fed chair who'll cut rates even where not supported by inflation and employment numbers, whereas the ECB is more disciplined and less subject to political interference.