SEOUL, South Korea — The United States flew long-range B-1B bombers in a show of force against North Korea on Tuesday, days after the powerful sister of North Korean leader Kim Jong Un vowed to resist a U.S.-led push to eliminate the North’s nuclear program. North Korea often reacts to the U.S. deployment of B-1B bombers and other powerful military assets with missile tests and fiery rhetoric. Tuesday’s flyover of the U.S. bombers could draw an angrier response because it happened when North