An Australian writer and businessman who has been detained in China on national security charges since 2019 has been declared guilty and was given a death sentence with two years’ probation on Monday, according to the Australian government, in a blow to warming relations between Australia and China. If the businessman, Yang Hengjun, does not commit any crimes in those two years, the sentence can be commuted to life imprisonment, Penny Wong, the Australian foreign minister, said in a statement. She described the verdict as “harrowing.” The long detention of…