Yes, our good friend and ally the Soviets attacked Finland and ultimately seized some of their territory (after embarrassing themselves for a few months to a much inferior opponent in terms of numbers). Not only that, the Fins had the perfect opportunity to help the German Army Group North cut off Leningrad completely during Barbarossa and declined to do so. Had they done that Leningrad probably would have fallen and Army Group North could have been largely funneled to either the center or south.
It is funny how the history we are taught almost never even makes mention of what a grotesque ally we made with the Soviet Union.
Ask most Americans what started WW2 and if they know anything about it at all they will say what our History books and various documentaries teach us - that it was started by the German invasion of Poland. So England and France declare war on Germany for the invasion of Poland - which not only did the Soviet Union do the very same thing, they actually seized MORE than half of Poland (along with the Baltics, etc). And on top of that, after the war ended, the USSR kept Poland as a satellite state. So we essentially go to war to save Poland, and ally ourselves with the USSR who militarily stole even more of Poland than Germany did. In some ways the whole thing is comical.
https://en.wikipedia.org/wiki/Finnish_invasion_of_Ladoga_Karelia
You might want to read about Finland invading all the way to Lake Lagoda and cutting off the northern half of Leningrad. But thankfully Leningrad hung on and those extra nazis weren’t freed up to go elsewhere.