In a stern warning to Taiwan and its allies on Sunday, Chinese Defence Minister Dong Jun said anyone trying to separate the self-governing democratic island from China would be “crushed and bring about their own downfall.” Dong, speaking at the Shangri-La Dialogue security conference in Singapore, vowed that the Chinese People’s Liberation Army would act “resolutely and forcefully” to prevent “Taiwan independence,” according to Chinese state broadcaster CCTV. The defence minister also indirectly attacked the US, which sells weapons to Taiwan. External forces are increasingly undermining the “O…