The Western allies trying to negotiate a way to protect the Strait of Hormuz for energy shipping face a stark reality: a similar effort in the Red Sea that started years earlier cost billions of dollars and ultimately failed against Yemen's Houthis. The costly Red Sea experience - four ships sunk, more than $1 billion in weapons expended, and a route that the shipping industry still largely avoids - looms over the more complex Strait of Hormuz, the shipping artery used by roughly a fifth of global oil and liquefied natural gas supply and now blocked by Iran, a more formidable adversary than the Houthis.