If the US buys its own bonds, then because of the status of being a reserve currency, they basically buy their own currency. If foreign governments would start to ease massively, then I suppose the currencies would weaken.
Now, you may say, “Well, why did the dollar strengthen amidst the fact that the US has printed money?” Well, there are some reasons. First of all, maybe the US dollar is not the ugliest among the several sisters, and two, because of the increase in oil production in the United States, the trade deficit has narrowed, and so the dollar can be strong for a while. I don’t think it will last, but the consensus is that the dollar is the strongest currency around. And these other countries, say if Thailand or Singapore or Indonesia would start to print money, then they would weaken their currencies, or that would be the perception.
- Marc Faber via Sprott Money