If confirmed, recent reports indicate that Yemen's Houthi rebels may pose a bigger threat than they once did to ships in the Red Sea. (MOHAMMED HUWAIS/AFP/Getty Images)

An attack on a ship in the Red Sea raises fresh concerns about Yemen's civil war. The apparent use of an anti-ship missile by Houthi fighters, if confirmed, would indicate that the group has acquired new capabilities, raising questions about the security of shipping in the waters off the Yemeni coast and the effectiveness of an arms embargo against the Houthis. If not the sign of a new weapon, the attack could suggest a shift in the group's tactics that may equally threaten ships in the Red Sea. Click here to continue reading…