The China/trade war, and now Iran, are both self-inflicted wounds, issues that didn't have to be, at least not right now. Without these disruptions, the Fed could have had several more years of normalization to get its house in order to restore its 'toolbox'.
As things stand now, the Fed's toolbox remains 2/3 empty, and allowing that situation to persist could turn out to be the biggest blunder in history.
On the other hand, it may have been planned that way (having the Fed 'tapped out') as a prerequisite to justify the transition to the SDRs. We know the SDR is their long term goal anyway, the only question being when, and how to pull it off. Maybe 'when' is now.