Perth has become the third Australian regional capital forced into a business-crippling lockdown — joining Sydney and Darwin — as the delta variant spreads nationwide.

Prime Minister Scott Morrison’s balancing act of keeping Australians safe and the economy open is becoming increasingly precarious as the outbreak worsens.

His government’s decision 15 months ago to close international borders was pivotal to Australia’s success in curbing community transmission, allowing life to largely return to normal and the economy to bounce back.