Lets say Martians attacked.
As they say in Yiddish, "So nu?"
I.e., I'm not sure what your point is there.
But you are reminding me that there's no way that an independent Communist state would be peaceful with the other states. It's not the Progressive way. It would be a failure as a state, itching to grab assets beyond its borders, and eager to bring in allies from overseas to help. They've been doing it since 1918.