Comment by hongsy

Reminded me of this https://en.wikipedia.org/wiki/Impossible_trinity

The impossible trinity (also known as the impossible trilemma or the Unholy Trinity) is a concept in international economics and international political economy which states that it is impossible to have all three of the following at the same time:

    - a fixed foreign exchange rate
    - free capital movement (absence of capital controls)
    - an independent monetary policy