By Idrees Ali and Phil Stewart WASHINGTON, July 22 (Reuters) - A Houthi threat to impose a naval blockade against Saudi Arabia in the Red Sea could significantly widen the Iran war and strain a U.S. military already focused on stopping Tehran's attacks across the region, current and former U.S. officials said. Yemen's Iran-aligned Houthis said on Monday they would not allow ships to load or unload at Saudi ports, potentially blocking Saudi oil exports and choking off an additional 7% of global oil supply.
