They keep declaring and lifting states of emergency.
They keep declaring and lifting states of emergency.
The state of emergency keeps being declared and lifted.
A state of emergency has been imposed and lifted repeatedly.
英語では keep + 動詞 で「何度も〜する」、repeatedly / over and over / on and off で「繰り返し」、そして “declare / lift” のペアで「宣言する/解除する」を作ると自然です。