Are you talking about Pete Seeger or someone else?
At the end of the French and Indian War the British government signed treaties with the Indians in the Ohio territory to restrict the American colonists from moving into there land. The American colonists ignored this British treaty, and started settling in the Ohio, Kentucky, and Tennessee areas. The British government, unlike the American government in the following century (which very seldom honored the treaties they signed with the Western tribes), tried to honor their treaties with he Indians and keep the Americans out. This brought the Americans and British into confrontation and was one of the main factors that led to the Revolution.
This is the definition of the word obligation.
Russia defeated Napoleon by starving and freezing his army to death. During the invasion, French troops were forced to march through miles of snow in extremely cold weather, without the proper clothing and supplies to survive it. The Russians purposefully burned down their own villages so that the French could not raid them for supplies. By the time Napoleon reached Moscow, his army's morale was extremely low and he had sustained heavy losses, and he was forced to retreat soon afterward. Russia's cold weather that makes it almost impossible to invade is often called 'Russian Winter' or 'General Winter'.
Hope this helps!