A reasonable scale of foreign exchange reserves and the control of currency structure is the core issue of foreign exchange reserves management theory.

外汇储备管理理论要解决的核心问题是外汇储备的合理规模和最优币种结构的控制问题。

youdao

The first is that if you can issue more money as and when you want, which you can if you control your own currency, then if the banks of the financial system get into trouble then you can just print more money to help them out.

FORBES: Eurozone Leaders: Now They're Making the Crisis Worse Through Stupidity