Explainer: Why did the US and UK just launch airstrikes in Yemen?

LAST NIGHT, US and British forces bombed more than a dozen sites used by the Iranian-backed Houthis in Yemen in a massive retaliatory strike using warship-launched Tomahawk missiles and fighter jets. This development comes as tensions have been rising after Iranian-backed Houthi rebels began striking at ships passing through the Red Sea in recent weeks. The Islamist group claims it began striking a narrow strip of sea between Yemen and east Africa, which is a key international trade route, in a bid to end Israel's air and ground offensive against Hamas. The overnight strikes on Yemen are the most significant…