Of course France, Spain, and the Dutch Republic jumped in on the side of the US for purely political reasons but how did the intellctuals and the politicians of Prussia, Russia, Austria, the Papal States (esp. the Pope), and the Ottomans react to the Revolution?
Russia and Austria declared “armed neutrality” which essentially meant that they considered the American Revolution to be a war between sovereign states, ergo that the United States was a sovereign belligerent rather than an internal British insurgency.
As for the Ottomans, I assume they welcomed the opportunity to have a new “customer” for their Mediterrainian protection racket. After 1776 Americans ships were no longer covered by the tribute paid by the British.
We tend to think of the American revolution as a pretty major event, but you have to put it in perspective. At that time, the U.S. was not a major power. We were a rinky dink little country that most people didn’t care too much about.
That said, other countries did take some interest, if (as you noted) it served their own political goals. France, Spain, etc. saw this as an opportunity to weaken the British. The Prussians were divided on the issue. Some supported Britain and some supported the U.S. There were quite a few people of Germanic descent in the U.S. (where I live in PA was originally mostly German speaking) but there were also many Germanic people who were loyal to Britain at the time as well.
A lot of the early founders of the U.S. had been protestants, and the U.S. was very anti-catholic for much of its early history. Needless to say, this didn’t exactly endear us to the pope.
The Ottomans were probably a bit too wrapped up in their own problems to care much about what happened to us.
Austria probably didn’t care too much about us either, but they did have an alliance going with France at the time. They probably also saw it as an opportunity to beat down the British a bit. France and Austria had been teaming up against Britain and Prussia since the 1750s or so.
Catherine the Great had her own problems in Russia at the time. She was also of Germanic descent and had a lot of the same conflicted issues as the other Germanic folk in Europe. Britain tried to hire troops from Russia, but Catherine turned them down. Russian politics had been generally allied with France and Austria in the decades leading up to the Revolutionary war.