When the coronavirus flared in China’s capital this week, Beijing canceled flights, suspended reopenings and described the situation as “extremely grave.” But with cases rising in some U.S. states, local officials have balked at even requiring people to wear masks. In the United States, which has the most confirmed cases and deaths in the world, authorities wrestled Wednesday with balancing demands for constitutional rights and personal freedom with warnings from health officials that being lax will have deadly consequences.