In the Seven Years' War, the main combatants were:
France
Austria
Russia
Sweden
Spain
Saxony
Sardinia
vs.
Prussia
Great Britain
Portugal
Hanover
Bruinswick-Wolfenbuttel
Hesse-Kessel
Iroqouis Confederacy
The war at that time was dire for Prussia, as it was speculated that his safety was not secure. The British threatened to withdraw support, and the Russians had taken the last Prussian Baltic portn. The Prussians faced invasion from fourt sides: from the West, France was storming the Rhine, from the North, Sweden was capturing Pommerania, from the south, the Austrians were continuing to ivade Silesia, and from the East, the Russians were sweeping through Prussia proper.
Had Empress Elizabeth not died and her Prussophile son not come to power, what could have happened to Prussia? If it collapsed, how could this affect the rest of Europe? Great Britain? The colonies in America?