The Treaty of '66 was clearly not something that could see the light of day. If word got out that France and Austria were joining hands to carve up the European Continent, wouldn't the London Government go mad?
The European Continent needed to maintain a balance, but not this kind of balance. If a Greater France and a Great Holy Roman Empire truly emerged, Europe would become a tripod. By then, there might very well be no fourth country left on the European Continent.
Like Pandora's box, once the thing called ambition had been opened, it was hard to put it back in.
What Napoleon left the French was not merely a string of glorious victories, but also a dream of becoming a great power. Given the emotional nature of the French public, once their passion for expansion was stirred, half of Italy and Belgium would hardly satisfy their appetite.
Adding Spain and Portugal wouldn't be excessive, would it? Napoleon had occupied Spain back then; they had to carry on that fine tradition!
If the French unified Western Europe and Austria unified the German lands, would Switzerland and the Netherlands, caught between those two behemoths, still have a choice?
Either they joined one side voluntarily, or they were forcibly annexed. Such was the fate of small countries.
Nor could the three Nordic nations, drifting apart from the rest, hope to stay unscathed. For strategic reasons, the Russians would not let them go either.
If all three great powers expanded outward, the British could only stare dumbly. Even if they wanted to interfere, they would be unable to—and before everyone fell out, they might be cleared off the board first.
The three nations even had a basis for alliance. Once they completed their expansion, they would certainly need time to digest