European climate activists have staged protests and posted messages in support of Palestinians, prompting political backlash and raising internal questions about their solidarity with other humanitarian causes. Long-running violence in the Middle East exploded on 7 October after Hamas militants killed 1,400 people in southern Israel. Since then, Israeli strikes have killed at least 5,087 Palestinians, 2,055 of them children, according to the Hamas-run health ministry in Gaza. Dutch authorities detained 19 activists from Extinction Rebellion on Monday after they occupied the entrance to the international criminal court and claimed Israel’s prime minister, Benjamin Netanyahu, had committed “war crimes” and...