If a country prints money and distributes it between the people, it causes inflation. But what if a country prints its own money to spend ONLY abroad, which would allow a country to buy whatever it wants. What's wrong with this logic?
In order for one country to spend in another, it needs to exchange its currency for the currency of the other nation. This is done through something called the foreign exchange market. Like most markets however, the laws of supply and demand apply here too. If a country suddenly starts printing a lot of money, the actual value of its money in the foreign exchange market will go down (due to its increased supply). This will ultimately mean the currency will depreciate with respect to others, and will thus have lower buying power.
This wouldn't work - for the money to have any value abroad, it has to find its way back to the source country.
Consider an example; the President of Ruritania wants a Swiss watch. He prints a thousand Ruritanian dingbats and sends them to his ambassador in Bern with the instruction to buy him a watch. However, the Swiss watch-maker doesn't want to be paid in dingbats - he wants Swiss Francs. So the ambassador goes to a Foreign Exchange (Forex) broker and asks to buy Swiss Francs using Ruritanian dingbats. What rate does the Forex broker give him? The broker has to consider what he could do with the dingbats - all he can do is sell them to some Swiss guy who needs dingbats for some reason. So it's the demand for dingbats in Switzerland that determines the rate.
Let's assume the Forex broker gives the ambassador some Swiss Francs and off he goes and gets the watch. What happens next? The broker sells the dingbats to a Swiss importer who is buying Ruritanian apples. The Swiss guy uses the dingbats to pay his supplier in Ruritania and now, the dingbats have ended up back in Ruritania!
So the Ruritanian money supply has increased and, despite the best efforts of the President, inflation is stoked.
Something close to what you want would be Special Drawing Rights, which were created by the IMF to serve as an international currency without the problem of a national currency having to both meet the needs of international trade and domestic economic goals.
China does, in fact, do something like this! It has two currencies - one for use internally and one internationally. It was explained better than I could by Adam Townsend on Twitter: https://twitter.com/adamscrabble/status/1094717028009689089
Thread unrolled: https://threadreaderapp.com/thread/1094717028009689089.html
The ‘onshore’ currency is the Renminbi (RMB) or yuan and also called the CNY. It is only used to pay bills on the mainland. The onshore currency can’t be used for international transactions. There... is no real market for the exchange rate, instead the People’s Bank of China (PBOC) comes up with a price every day thru an unknown equation, and then trades around it.
The “offshore” currency, also called the yuan or CNH, is used for international clearing and trading.
The CNH has a completely separate set of demand and supply conditions from the onshore RMB.
The Chinese have it both ways, huge inner stimulation to appease the people. Strong external currency to maintain purchasing power outside. By controlling the supply of CNH (offshore money) outstanding China can create a CNH shortage. They’d just buy the offshore currency to drive the value/price up. Alternatively they can sell the offshore currency, flooding the market with CNH to drive the value/price down. For example, when a foreign Purchaser of goods has to settle the transaction, and there’s a shortage of settlement currency (CNH), his/her cost goes up.
Conversely, if there are boatloads of CNH available his/her cost goes down.