I understand the "postwar" here to mean "after WW2". After this war, France was capitalist, while Czechoslovakia found itself in the socialist camp, lead by the Soviet Union. Connected to this is the fact that France, like many other capitalist states was member of NATO and Czechoslovakia of the Warsaw Pact.
It was terrible because you never know when or how you could get caught it was kind of like a path if one house of the underground was found the person would be forced to tell the other houses. And as for the slaves they were never aloud to go back ounce they escaped because their slaveowners would force them to tell where the others are
By the conclusion of the Revolutionary War, the balance of power in North America had shifted away from the Native Americans and toward white Americans. British power continued on in Canada, but the French were wholly absent as a regional force, so Native Americans could no longer negotiate between the great powers.