The US has launched air strikes across Yemen. The military action is the largest and most significant President Donald Trump has ordered during his second term. Targets included the capital Sanaa and city of Hodeidah, a vital port for one of the world's poorest countries. The US says such unrelenting lethal force will continue until the Iran-backed Houthis agree to stop their attacks on shipping in the Red Sea. The Houthis have targeted Israel and commercial vessels since early in Israel’s war on Gaza – saying the attacks are a show of solidarity with Palestinians. So what are the risks of all of this?