Moonsoo, a Republic of Korea citizen, went to San Diego, California, on a vacation. Because he liked San Diego, Moonsoo purchased five acres of land, on which he wants to build luxury condominiums. He also bought the majority interest in a construction corporation that specializes in condominium construction. Moonsoo could not get the zoning clearance to build the condominiums, so he sold both the land and his stock in the construction corporation. Is Moonsoo taxed in the United States on his gains from these sales?