Iran is sending advanced weapons and military advisers to Yemen's rebel Houthi movement, stepping up support for its Shiite ally in a civil war whose outcome could sway the balance of power in the Middle East, regional and Western sources say.
Iran's enemy Saudi Arabia is leading a Sunni Arab coalition fighting the Houthis in the impoverished state on the tip of the Arabian peninsula — part of the same regional power struggle fueling the war in Syria.
Sources with knowledge of the military movements, who declined to be identified, say that in recent months Iran has taken a greater role in the two-year-old conflict by stepping up arms supplies and other support. This mirrors the strategy it has used to support its Lebanese ally Hezbollah in Syria.