In the beginning of The Cay by Theodore Taylor, why were the residents of Willemstad worried and fearful?

At the beginning of the book, the residents of Willemstad in Curacao, then a Dutch island off the coast of Venezuela, are worried because it is 1942. The Germans have just bombed the Lago oil refinery on Arbua, the neighboring island. Then, the Germans blew up six small oil tankers on Curacao that bring crude oil from Lake Maracaibo to the oil refinery to be turned into gasoline and diesel. The Germans are attempting to...

At the beginning of the book, the residents of Willemstad in Curacao, then a Dutch island off the coast of Venezuela, are worried because it is 1942. The Germans have just bombed the Lago oil refinery on Arbua, the neighboring island. Then, the Germans blew up six small oil tankers on Curacao that bring crude oil from Lake Maracaibo to the oil refinery to be turned into gasoline and diesel. The Germans are attempting to take over the islands by depriving them of oil, and a German oil tanker has been seen off the coast of Willemstad. World War II has come to the islands in the Caribbean, which makes Phillip's mother and others on the island very worried. Phillip's mother insists on returning to her native Virginia, but the boat she and Phillip are traveling on is torpedoed en route.