The Wall Street Journal published on 12 June 2024 an article titled "How an Iranian-Backed Militia Ties Down U.S. Naval Forces in the Red Sea" by Gordon Lubold.
The US has spent about $1 billion on munitions used in defending the Red Sea, conducting more than 450 strikes and intercepting more than 200 Houthi drones and missiles since the beginning of attacks on international shipping last November. Iranian provided drones and missiles are relatively cheap by comparison.
There is concern that this level of US and UK response cannot be maintained in view of the demand for weapons from Ukraine and Israel.
