Question: Why couldn't Petrovich persuade Austria to invade Prussia?
Sentence: Aleksey Petrovich, Graf (count) Bestuzhev-Ryumin, grand chancellor of Russia under Empress Elizabeth, was hostile to both France and Prussia, but he could not persuade Austrian statesman Wenzel Anton von Kaunitz to commit to offensive designs against Prussia so long as Prussia was able to rely on French support.
Answer in sentence: yes