Analysis-Houthi advance in Yemen puts U.S. in a new bind

By Humeyra Pamuk, Simon Lewis and Matt SpetalnickWASHINGTON, Sept 12 (Reuters) - A lightning offensive by the Iran-aligned Houthis has put the militants in a position to control a crucial Middle East waterway, creating a major new problem for U.S. President Donald Trump as his war with Iran grinds on in its seventh month.