The Houthis have endured a half-year of American strikes, delivering US President Biden a major foreign policy defeat.

Since January 2024 the US has launched salvos of missiles, costing $1m to $4.3m each, against Houthi targets. The costly attacks led Senator Jack Reed, chairman of the US Senate Armed Services Committee, to admonish US President Joe Biden in January, saying: “So you’ve got this issue that will be emerging of how long can we continue to fire expensive missiles.”

To date, the US has lost at least three Reaper drones over Yemen, each costing $30m.

Estimates of the total cost of the operation range between $260m and $573m per month – that is, between $1.8bn and $4bn so far.

None of the US and its allies’ actions in the Red Sea have stopped the disruption of shipping lanes. Shipping and insurance costs have soared.